Afternoon fellas. Licensed tech here ( 20 years ) Need a hand trying to figure this one out... Details: Cat 980G. 4 batteries, 2+2 set up, 24 volt system. ( obviously ) - When batteries ON, frame is grounded 100% - When batteries are shut off, frame energizes to 95% source voltage. ( 25.6 source voltage, frame energizes to 22.5 v ) - All battery positive ( + ) cables are secure with zero `rub through` along frame &/or P-clamp locations. - Starter NOT shorted - Alternator NOT shorted - Positive junction block NOT shorted - Ignition switch NOT shorted - Injection pump shut off relay de-energized - When hood actuator harness disconnected from positive junction block post, frame energization drops to 11 volts. - Harness NOT rubbed through Ideas, thoughts... ?
So to get this straight, with the master switch off you are putting a DMM between battery negative and the frame, correct? If that's the case then it's to be expected. Voltage will feed back through any closed circuit, bulb, relay etc.
Cmark: The frame of the unit becomes energized. When utilizing a PowerProbe ( fancy test light ) I can pull over 22 (+) volts from the frame, body, engine, etc... and when I supply a ground to the frame I can get amperage ( essentially short circuiting )
My question is, what was the original problem that led you to this point?
Cmark is right, your power probe will show voltage but if you tried to use that voltage to light a test light it won't. I ran into the same thing, had me scratching my head until I figured out my tool was smarter than me! I had never noticed they did that before I had a power probe that makes it so easy to check everything.
Where are you checking for voltage at? Are you going from the frame to the negative post on the battery?
Vetech63: I am currently installing `battery shut off indicator lights` to notify operators that they have left their batteries on. It is an small button type LED mounted by the steps as a visual cue. Wired to a constant, non-keyed voltage source and frame ground. I noticed that the LED only dims out, when batteries are shut off. This got the ball rolling. However, an incandescent light will extinguish. ( P.S. none of my other units do this with LED`s installed ) JPV: The frame will illuminate a LED @ 6 volts. When there is NO LOAD I am measuring 22v @ frame. When loaded, via an LED, the frame drops to 6v. John C. : Power Probe hooked up to batteries ( 24v pos & Neg terminal ) I read 22v on frame.
If an incandescent light in the same circuit will extinguish then I recall when a large number of lights (incl. the red/green payload indicators) were "upgraded" from incandescent to LED on Cat haul trucks it caused all sorts of weird behaviour in electrical/electronic systems. Memory is a bit fuzzy as regards the detail though.
I see, I didn't realize it would light an led, I think it is normal but a little weird, like I say I have noticed the same thing but not until I owned a power probe.
There must be something allowing current between battery neg and ground. If you disconnect the batt neg cable at the back of the master switch what happens? Try disconnecting each battery in turn. An LED only needs milliamps to light so, for example, corrosion between a battery post and battery hold down clamp can pass enough current. (I assume you've checked for something wired directly to batt neg; aftermarket lube system, radio memory, payload indicator, etc?)
It looks like your in good hands here. I know people that have tried multiple ways to indicate master switch turn off...….if its a light, they don't see it...….if its an alarm, they don't hear it...….if its fart spray, they don't smell it. The only way I KNOW it would work is if you could rig up something that would gut punch them when they climb out of the cab.
The master switch thing isn't hard at all. Dead batteries once from switch being left on and you get a verbal warning, left on twice you get a written reprimand and a warning that the next instance might be your last at this company. Third time is a charm. You can tie that in with running out of fuel, not checking fluids and not greasing the machine.
Now if this was one of the older machines with the battery disconnect right next to the seat I'd suggest putting the disconnect key on a leash around the operators neck
You guys are awesome. Not a single one of our operators do these things. Same story across the whole world, I guess. Had an issue with guys not checking fluids, etc... so I went in to work at 4 am, removed every single key from the machines and zip tied them to the dipsticks. Sat back, and waited... Not a single operator found a key! However, I recieved 13 calls that "Someone had stolen all the keys" HAHAHAHAH ! IT WAS AWESOME. But disconcerting at the same time...
Cmark: I regards to your last post. I have exhausted all of those suggestions before seeking online help. We think alike.
Not familiar with your machine but....does it have a solenoid like a komatsu that,when energized,fires up the electrical to the rest of the tractor? There will be a hot wire to energize it,hooked up to switched power,possibly through the key switch because all other electrical is dead at this time. Maybe the solenoid is shorted internally to the frame or the wire to energize it is rubbed and shorting.A schematic would be awesome to let you know what goes where. Gotta love electrical problems....10 hours to find and 10 minutes to fix.
Tractormech: We have Komatsu's as well ( 250's, a 320 and a couple 500's ) I do know the solenoid you speak of and our 980G doesnt have one.
I'd like to see what happens when the "product link" fuse is removed.
Some of the newer machines have a small wire like 16 g that hooks to a separate small post on the master switch. This wire is for the keep alive circuits in the various controllers and is always energized.
I nearly got fired for something similar. We started a new jobsite and I checked each machine as they came off the lowboy (10pcs). Put 10 unit numbers in a hat, and picked one. Taped a $20 bill to the engine oil dipstick on a Caterpillar 330CL. Had other obligations and didn't return to that site for three weeks. It was an overcast day, light breeze, I'm guessing mid September, about 1pm, and as I drive in, I see the Cat 330 at work. Tell the operator that I had to get something from under the engine hood. He idles down, I climb up top. As I'm removing the dipstick, a curious operator watches from inside the cab. I nonchalantly unfurl a $20, all the while avoiding any more eye contact. I close the hood, climb down, get in my truck and proceed to the other side of the jobsite. I heard absolutely zero chatter on the 2way radios or the CB, but, it took 11 minutes for the owner to ring my phone. Turns out that they were test demoing a new excavator operator that day. To his credit, he did work until end of shift. Was never told if he quit, or was released for underperforming as a ditch digger.
heymccall: I am unsure of what you are calling the `product link` fuse. I have in fact pulled fuses, systematically in an attempt to locate the problem circuit, to no avail. ( Same as diagnosing ghost draws ) kith: This particular machine does not have an additional `keep alive` wire. Straight forward, two post switch.
I don’t think a 980G (2KR I imagine) is new enough to have Product Link installed, unless someone’s done a retrofit somewhere.
LOL, he means the 'smart phone fuse' even our 94' hitachi ex has the keep alive circuit to protect the computers from rapid on/off spikes, it is designed to keep the power alive for a minute or two after everything is shut down... and is controlled through the alternator to determine if the machine is running so when the alt. goes bad it can cause funny things to happen.
Product link wasn't a standard feature for G model wheel loaders. If you find a machine with it, someone paid to install it after the initial sale. Product link is powered down when you open the disconnect on newer machines that I have experience with. What I might suggest is to unhook the battery wire to the disconnect switch with the light hooked up. I've seen the ground disconnects bleed through when they get old. I'm not familiar with the power probe product so was wondering if it might be a little too sensitive to voltage?
John C.: I do believe we are on a similar thought process, re: Power Probe . However, no matter what type of electrical tool is used to diagnose, it shouldnt `arc` out when touched to the frame ( or when an artificial ground is supplied to frame, that it creates a spark @ initial contact... ) The battery switch is in perfect working order, not shorted internally or shorted to mounting area. P.S. You totally need to get yourself a Power Probe. Hands down the best money I have ever spent on a tool. Ever. Once you use one, you will NEVER go back to jumper wires, test lights, squirrel nests of wiring, alligator clips, etc...
Now you have me curious, can you check any of your other cat machines to see if they do the same thing? I still kind of think it is normal, my guess is you are seeing the power draw that the battery switch is there to cut off but I am probably wrong if past history is any indication! Second the power probe comment, wouldn't be without one.
JPV: Unfortunately, my sister machine has been sent out to a jobsite. However, the battery disconnect indicator LED that I installed on that machine turns on and off perfectly... Frustrating...
I see, sounds like you have something going on then, will be watching to see what you come up with, those other guys had some good suggestions.
JPV: `` sounds like you have something going on then ``... Truer words have never been spoken. err, typed...
Disconnect the ground lead from the master switch and remove all four battery negative terminals. The problem SURELY must be gone by now. Start reconnecting things one at a time until the problem reoccurs. That HAS to lead you somewhere.
Tex32, Probably not the problem on your but many years ago I had a strange electrical problem that I don't recall the details of but just recall finding voltage going some place I didn't expect it to be. What I do recall is the source of this strange "leak" of electricity was a dirty battery! This was an old Mack truck used off-road in a sand and gravel pit. Between all the moisture and dirt and the fumes inside the battery box putting a touch of acid on top of the battery you could get a volt meter to read a few volts just by touching one lead to the + terminal and the other lead to any place on top of the battery half way between the two terminals! I could see an accumulation of dirt and corrosion some place on either the disconnect switch or even between one of the battery hold downs and a negative battery terminal causing a "leak" of electricity that was able to get a LED to glow. Like Cmark says one way to find the source is to disconnect every negative terminal connection and then reconnect each one one at a time to see which one lights the LED. And if the LED lights with all four negative cables off the battery clean around each one till LED goes off! And please let us know what the solution was, nothing worse that someone getting a problem solved and not letting us know so we can point the next guy with a similar problem to a solution.
So why did you almost get fired?
Another item I might ask is if someone wanted to listen to tunes and hooked up a power lead somewhere to run a voltage drop or they just fed off one battery to run it. I'll look into the power probe.
Cmark: I did this as well. The energized frame continues, even when all the NEG terminals have been removed. This is what lead me to believe that I had a POS cable or circuit rubbed through somewhere in the machine. Upon checking and rechecking my harnesses, I determined them to be in good working order. As earlier stated, I`ve even pulled all fuses, circuit breakers, bus bars and relays, to systematically isolate any problem component or circuit. kshansen: I originally did in fact, have a draw or drop across the batteries. Our machines run in a steel plant, and the batteries had kish & coke built up on top of them. I had measured continuity between the POS terminals and the hold downs. This was the 1st item rectified within my electrical gremlin journey. Batteries are now 100% clean and isolated. I even went as far as to remove & inspect the battery cases themselves to eliminate the possibility of them feeding voltage into the batt box. John C: There a no additional added circuits within the system. This is fun, eh? **totally Canadian slang right there**
This is a voyage of discovery somewhat akin to Columbus discovering the New World......... OK, so you pulled all the neg cables, still had the issue. then you went on to pull fuses, CBs, etc. Do you have the Electrical Schematic for the machine..? A Serial Number and an email address gets it for you. Another question. Does it still have a 3406 or has it been re-engined with a C-Series engine at some point..? The only thing I can possibly think of is that there is +ve power feeding something that does not go directly to the fuse/circuit breaker panel, or that the main 4 SWG power cable from the batteries to the fuse box is leaking power somewhere where it passes through a main connector. You say it is a steel mill application. Are all your harness connectors sealed with non-conducting tape..? If not then what's the chance of iron dust that has got inside a connector somewhere allowing power to track in weird directions..?
What about a very dirty and corroded battery box and/or a metal battery holddown across the top of the battery picking up some power from the terminals on the battery. A LED takes very very little current to run.
Nige: I do have the electrical schematic ( Thank God ) This engine does have a 3406. I agree with your 2nd paragraph and believe that this should be the area of concern... AND your 3rd is absolutely dynomite !! Honestly never even had this cross my freakin` mind.... Now to inspect. Every. Single. Deutsch, Weather Pak, Terminal and plug. In the. ENTIRE. MACHINE...
franklin2: See previous posts.
Sometimes even a blind squirrel finds a nut......... Seriously though, we are in a very wet environment (think 200" of rain a year). We waterproof all our harness connectors with a product called Senson Electroguard grease and waterproofing tape. I did post a copy of a Cat Best Practice document somewhere a while back detailing how to do it.......
HeavyEquipmentForums Post #13 has the attachment I spoke about.
Smile........your on Candid Camera!!!
I don't recall you mentioning working in a steel plant up front in the thread. I have had to do inspections of that vary model in a steel plant in my area and I have to say those machines really look like hell when they are done with them. These units pull hot slag out of the plant and then dump it into a pile where water is continually sprayed on the stuff until it is cool enough to load on a truck and hauled out back to finish cooling. All that slag stuff coats the entire machine and the heat with water requires extra guarding and the sealing measures Nige has spoken of above. If your machine is operating in the same type of environment I feel for you and your job. Sounds like you have all the straight forward answers covered and I don't have anything to add except let us know what you find out. Good Luck!
John C: Thank you. As far as feeling for me goes, no worries there. I`m the working foreman here and get to delegate the grimey jobs. We have about 20 pieces in the steel plant, under contract. The rest ( about 50 pieces ) are earth moving, toilsoil handling, etc... Along with screening plants, tractors, trucks, tri-axles, pickups, classic cars, blah... blah... blah... Makes for a busy crew. Of THREE...
Your frame is showing positive charge measured against the negative battery terminals, right? and you have a ground cable disconnect? You'll have to disconnect the positive harness and reconnect one by one to show what's leaking. For one, I've used a power probe and don't find it more useful than thinking the problem through and testing with a $2 multimeter. I didn't notice any mention of the alternator? the alternator is typically attached directly to the batteries with a fusible link somewhere in the wire. The rectifier leaks voltage, more or less.
Delmer: Original post indicates my alternator was found to be GOOD. No internal shorts & rectifier bridge in good working order. `` For one, I've used a power probe and don't find it more useful than thinking the problem through and testing with a $2 multimeter. `` - CONGRATS... .. .
This is getting weird. All four battery negative terminals disconnected and an LED between positive and frame still lights, correct? And no physical damage to any of the batteries allowing current leakage to the frame? Doesn't seem possible. Steel mill you say? Does it have fire suppression fitted? That will have an internal backup battery, probably in the box in the cab. Could be a possibility.
Okay, now you have got me laying awake at night thinking about this too. If I understand correctly, you have connected the frame to unswitched +24 v through an LED (diode), creating a circuit that goes from (+)battery to LED to frame to disconnect switch to (-)battery. When the battery shutoff switch is opened or the batteries are disconnected you now have an open circuit with (+)battery, LED, and frame on one side and (-)battery on the other. Since no current is flowing in the circuit, voltage across the LED goes to zero. Diodes have very small but measurable forward leakage current so it shouldn't be surprising that the frame eventually floats to the same voltage as (+) battery. As to the Power Probe, the published spec for input resistance to ground is 350K ohms, while the input resistance of the Fluke DMM that lives in my truck next to the Power Probe is 10M ohms. When I measured the input resistance to ground of the Power Probe this morning with the Fluke I got 120K ohms, much less than what is supposed to be and makes me wonder what yours is. When you clamp the power probe to (-)battery and probe the frame you have just closed the circuit. The Power Probe is not the best tool for investigating this problem and may be introducing some unintended effects. As to the LED being on with only one battery connection (and presumably the Power Probe not completing the circuit), I see more sleepless nights ahead. Steel dust? Parked next to the electric arc furnace in the mill? Grounded to earth through steel tire chains common in steel mills? ???
brianbulldozer : You are correct. Simply put, LED hooked up to a constant 24v supply ( not keyed ) and ground. When bats ON, the LED is illuminated, when bats OFF, the LED dims, but still stays on. This is what started all the confusion... It was at that point I discovered that the frame sports a +24v when the batts are off. No tire chains. No external voltage supply from another source. Just the machine sitting in my shop. As bad as this sounds, thanks for the sleepless nights... I'm glad I'm not the only one....
Back to the subject of the wiring harness connections, I recall major issues on 992Gs where the main power feed (4 SWG cable) to the electronics compartment/fuse/circuit breaker box was routed in with a machine harness containing a load of 12-16 SWG cables. There was one particular connector that often came "loose" because of the weight of the harness with that big heavy cable in it. If the problem was not spotted the power cable would burn up because of the arcing in the connector. Maybe a similar problem could be happening on your 980G with the harness being of similar design...? Not necessarily the burned cable, but maybe the arcing inside the connector. Our solution on the 992G was to route a new main power cable outside the machine harness and take it through the firewall into the Electronics Bay/fuse box on its own separate connector..
Nige: Since the [your] inception of kish filled dirty connections came about, I am in full agreement with this latest analysis. I believe that a bad connector within the machine MUST be the source of the back feed. The main connectors shown are a problem area for the 980's and will be re-examining them in the New Year.
Hi been following this with interest had something similar but with fire suppression years ago .Just for giggles disconnect the hydraulic and transmission ECM's behind the seat and see what happens Mark
If you’ve done this and still have power to the frame it can’t be a positive cable problem unless there is an alternate power source like fire suppression back up power.
Why do you want your operators to shut the master switch off? So the batteries don’t go dead? The batteries couldn’t go dead if there wasn’t a path for current to get back to the batteries, right? What I’m saying is you don’t have a problem. Use an ammeter instead of your power probe between the frame and negative post, you probably have very little current flow. I believe any newer machine with ANY electronics will do the same thing. That’s why you always get a spark when you connect a battery cable.
Because on these new machines, even though it would be logical to think that you should be fine by just turning off the keyswitch, in reality it does not work that way. My excavator is a 2014, and I have not added anything or modified the electrical system in any way. If you do not shut the master switch off, it is an absolute certainty that your batteries will be dead within a month, the only unknown is if they will be dead within a week, or four, I've experienced both. It caused me to have to replace the batteries after 3 years, when they should go 10 or more. The last time they were killed, one refused to take charge, and the other reversed polarity so thoroughly that I couldn't even hook a charger to it, that was a new one for me.
I can see you only read the first sentence of what I said
As for why turn off master switch, where I worked it was mandatory company policy. It was instituted after a few plants around the country had fires related to an electrical problem that started while machines were parked over night. Some to the point that the fire involved equipment parked near them. That lead to a policy of also not parking two machines within I believe it was 20 feet of another machine. And any equipment that did not come from factory with battery disconnect switches those had to be added to the equipment. I believe the only exceptions were pick-up trucks.
I guess it’s normal here to only read the first sentence of a post and then reply?
No, I read your whole post. And answered your question as to why *most* (in my opinion) people want the master switch turned off. But, hey, if ya want to argue or contradict, have at it.
No I read the whole post but was just mentioning why we were required to use disconnect switch for the benefit of anyone who might not see a reason for doing that. Sorry if I wasted everyone's time I'll shut up now!
What kind of a response are you looking for, because obviously we aren't giving it to you? You want to debate whether or not current draw is an issue, because that's all there is left? The bigger question is why the attitude??
I’m trying to tell the original poster that what he is seeing is normal! That’s it. No question from me, it is a statement.
Well, if I misunderstood your intent, I apologize, but you did lead off your post with three direct questions, and those were what kshansen and myself were addressing.
His problem is that the LED warning light he added to warn the operator to shut off the disconnect won't shut off when the disconnect is off. Apparently the LED will shut off on other machines. THAT part of the problem I understand.
An idea just occurred to me while going back and reading the entire thread. I hadn't posted anything other than a question about the $20 bill story because I don't comment unless I have something pertinent to add, but maybe this might be relevant? I read in an earlier post that the frame becomes positively energized. So, my question for the OP and others is the LED used on this machine identical to the others? If it is, then my thought is pointless. But, if it is a different LED, is it plausible that the one that stays lit is not polarity sensitive, and the others are? If the LED was polarity sensitive, it *shouldn't* light with a positive energized frame, because the ground wire coming from the frame is attached to the negative side. Maybe he can try an LED from a different machine to verify?
Here’s my challenge, go disconnect the battery on your car or pickup and use a volt meter to measure the voltage between your frame and the negative battery terminal. All our vehicles are broken according to the original post.
I just read this LAST page so I'm jumpin in the middle/end of this.. Why not just leave the tester hooked up like that & start pullin fuses 1 @ a time & check the meter as u go?? Might as well start at the LED lite source as that seems to come into question..{good thinkin shimmy}
You're overlooking something. On a normal vehicle, what you are demonstrating is perfectly normal, your DMM is taking the place of the negative cable. In the OP's situation, the master disconnect is switched off. Remove the positive cable as well and see if your meter shows voltage.
You’re wrong, Cat master switches break the ground only. I’ve been a Cat mechanic 26 years.
Yep, you're correct. I wasn't thinking when I posted that the positive always stays connected. So, I did a little digging, and discovered that my suggestion from an earlier post might be incorrect. I have thought in the past that some LED's are polarity specific, and some are not. From my searching today, i might be inclined to believe that is not the case. That being said, *if* LED's can only light with the correct polarity, if the OP's light is staying lit, he has to have voltage leaking around the master disconnect somehow.
I didn’t pay a lot of attention to the LED part, so no comment. When he said having voltage potential between the frame and negative terminal I immediately knew the situation, and there is nothing abnormal about that condition. Not trying to be an A-hole.
Does the machine in question have an ECM or other electronics? I'm the worst when it comes to electrical but have an odd issue with my new to me dump truck with a Cummins M11. It was a former plow truck and has 2 battery disconnects. One for 2 batteries and the other for the other battery(s). I run 3 batteries. I thought one of the battery disconnects was bad so I replaced it but the problem was still there so I only shut the one disconnect off. The other one when shut off causes one of the idiot lights on the dash to come on. I think I read somewhere that an ECM can store some voltage and thought that could be part of the problem. The idiot light stays off with the disconnect on. I can shut the 2 batteries off and the truck can sit for weeks and starts right up so I'm not worrying about the single battery being left on too much. There are stickers on the truck warning to disconnect both battery cables before doing any welding on the truck due to sensitive electronics(plow controls, GPS, etc.). Just wondering if there could be some electronic component storing energy?
Welder Dave I have seen several times that when people installed master switches that they never picked up the wires for the ECM as they are connected directly to the battery posts. Just something to look at.
Yes sir, has 3 ECM’s. And yes they all have keep alive memory connections that are hot with the key off. And when you connect the last battery connection they make a big arc.
There were some smaller wires at the battery but they were cut off and not used. It has to be grounding somewhere other than at the battery connection. The truck is only set up for the dump box now and a lot of the electric cables were chopped off. I have 2 or 3 more solenoid operated hydraulic valves but the wires going to them were chopped off.
Wow. This thread really blew up, while I was enjoying Christmas. Appreciate all the help and suggestions guys. I wish I could address all of the comments individually. ALL, and I mean all of your ideas and diagnostic practices have been attempted and thoroughly tested. Still the same issue. Same LED installed in all machines. Currently have 12 units wired with LED indicators. All work good. Another 980G sister machine was wired the same as well, without error.
May have already tried it but how about swapping the working LED from the one loader with the LED that is giving you fits from the other loader? Would not expect any change but at this point if it was me I'd be trying just about anything. Or have you tried an incandescent lamp in place of the LED to see if that does the same? It can be hard to trouble shoot things from a distance and sorry if these suggestions have been asked and tried already.
Ok, I re read the part about the LED. you want the LED dark with the master off, right? The only way to do that is to have the same voltage on both terminals of the LED, ie 0&0, 24&24 etc. it is normal to have the frame energized with the master off, I’m convinced of that. But if there is a small path to ground between the frame & negative battery post you will have a current flow through the LED & it will glow. Could be batteries that need cleaning or moisture in the master switch. I think you’re chasing your tail trying to figure out why the frame is energized. My2€
And the thing with LED's is how low of a power source (or ground source) they need to "glow". That was why I was suggesting a good old incandescent bulb that would require a better source of power or ground. This problem maybe just like the problems with gas engines with distributor, some of you might remember those things, you could get what was called "carbon tracking" the engine might run fine until the first damp morning then it would skip and backfire like crazy. As this machine is run around a steel mill it could be something like that, but iron oxide dust some place, which I believe was the point Nige was making many posts back!
This reminded me of the first time I bought compact florescent bulbs years ago. I came home well after dark on a winter night at about 10-20 below zero, I was wearing a sweater and walked into my pitch dark unheated living quarters by feel and suddenly I could see from something glowing on me. I looked down and the light was gone, but when I walked the CFL bulbs in the packaging, in the bags would glow enough through the bag to be able to see clear enough to walk. I took the package out of the bag, rubbed it on my sweater and they glowed just like a glow stick. LED's take half the power to make the light of florescents. And they like low voltage DC.
Yep almost like a crystal radio set, just need one diode...
Okay Ronsii's remark got me thinking, probably not a good thing, assuming this problem is not caused by anything serious that will end up burning the 980 to the ground. Would it be possible to add a small resistor in line with the LED to drop the voltage below the point the LED glows with disconnect off but still not prevent it from lighting up with disconnect on?
Just remember that very LED is actually providing the draw on the battery now and putting a resistor on it will make the draw even higher... it'll still be a very small draw... but... even so a draw
An LED cannot light up without current flow, and the master switch should stop the current flow when it’s off by disconnecting the negative battery post from the frame ground. There is enough of a path back to the negative battery post to light the LED. we’re talking milliamperes.
**AN UPDATE** Unit has been repaired. Found that someone had wired a capacitor, hidden in behind the fuse panel. For zero reason whatsoever. I have found evidence that this might have been a `Capacitor Prank` that someone went through alot of trouble making and wiring into place to shock the operator. The capacitor was getting charged through cab power when running, then when shut off it was backfeeding voltage through its casing and into the mounting area. The capacitor was well hidden, and had wiring going towards the steering column area. I can only assume that this was hooked up at some point in time, to a contact on the wheel, or even the joysticks... This whole thing threw me ( us ) for a loop... Thank you all for assisting throughout the journey.
There is a special place in hell..., never heard of that, unreal, Thanks for the update, I am impressed by whoever did it and by you for figuring it out.
Playing tricks like that might have been fun at one time but with all the electronics and ECM's on modern equipment the funny could go south fast if instead of shocking the operator it managed to fry or just erase programing in a computer flash file! Probably too late but maybe try dropping some hints that management is sending the capacitor out to a crime lab to have it dusted for prints. Might get someone a bit nervous! Like they say "Payback's a bitch!" Were you actually hunting for the problem when you found it or were you just working on something else and noticed something that did not look factory. Again thanks for the solution, too often there is a thread like this with all kinds of people trying to come up with ideas and then the original poster just vanishes. Anything else going on there? Don't be a stranger anyone who can find a solution like that can be of lots of help on this site.
Helluva job Tex.!!! I think Hansen said it all.. Don't be a stranger & thanks for the update..
Good job. That one would have pretty much taxed anybody to find. You go in there doing diagnostics to figure out what's not working right that the OEM put there, not with any suspicion that someone has been engaged in "extracurricular activities".......
GOOD JOB
Dam Tex !! You sure are a patient technician. Not many would have found that capacitor. The lowlife that installed it should be looking for a different employer. Good job !
Thanks everyone... Yeah, it was quite the journey. kshansen: ``Were you actually hunting for the problem when you found it or were you just working on something else and noticed something that did not look factory`` No, I was actually trying to figure out why the frame of the machine was being energized. Was installing a small LED indicator light to notify operator that they have left their batteries on. And when the batt switch was turned off, the LED was staying on, even though the batts were disconnected.
Tex, Be sure to come back to HEF. Forums like this need all the help they can get from people with the knowledge you have.
Tex, if I’m reading it right what ksh was asking is if you found the capacitor by accident while fixing something else in the fuse panel or were you still working on diagnosing why the frame was still energized with the master switch was off when you found it..?
Nige: Was still on the war path to figuring out the BS. P.S. - I haven`t been working on this the whole time...
Sometimes that helps, being distracted by other work lets the mind refocus. At least for me, I can sometimes get so focused on one plan of attack for a problem I can fail to see a different source of the problem. Like the problem I fought half of one summer with the 988H with "Plugged trans. filter light coming on. Once I was sure the filter and it's switch were not the problem we just ignored it for a while. Then I just stumbled on the fact that there was a bad trans. temp sender. It was not triggering an over heat problem but for some reason it was actuating the plugged filter indicator.
This confirms you did have an odd problem and were pretty darn smart at realizing there was a problem in the 1st place. Do you think someone did it to mess around with you or another technician? That's not a prank anymore. If I had a shop and someone did that they'd be looking for a new job unless they confessed 5 minutes into it.
Welder Dave: I believe it was a long ago prank that had since been disconnected on the operator side, but the capacitor was still hard wired in, and working... Good thing I didn`t get poked.