Been trying to track down an electrical problem it popped up a few months ago when a battery on the machine caught fire. Currently not working is wipers, radio, heat/ac, and espar. Anytime you try the wipers nothing happens and it blows the fuse for it. The computer works fine, shows the heather controls etc just nothing happens. Although I did hear some noise when I was changing the controls, i'm pretty sure the heater is just not getting power? I have checked all fuses, changed relays around with things that are working, no change at all. At least all the fuses/relays right behind the cab unless there are more elsewhere? I did see 2 breakers above battery box but not sure how to test those? Today above the battery box I opened the controller and the converter I believe it was, both look fine from what I can tell? I'm not sure where to check next on what it could be?
Good day I guess your machine has the Cummins engine ? if so you have some slow blow fuse's which I believe you are referring to. A battery issue that you outline sounds like overcharging. Suggest you check along the system with a Muti meter to establish what is shorting the wipers act. out. Kind regards Uffex
This may help
That's a tier 3 machine. Fuse and relay box behind cab. I suspect one of your accessory relays has failed. They're the ones closer to the top. 2 pins are larger than the other 2 On the bottom of the fuse box are a bunch of little black tubes, those are diodes. They need to be checked. Before any of that, however. Open the cover to the box and take a good sniff. If it smells burnt, odds are the pcb has failed. There are 2 sandwiched in there with a ribbon between the two. If you feel comfortable, carefully disassemble to where you can see in between there. If you see damage, well you know.
Yes that would be it. Unfortunately this happened like 3 months ago so I am going to assume any smell would be long gone? I didn't notice anything yesterday. I swapped all relays around to no avail, though a few in the top right I know I could just swap for each other and not for anything I can know for sure works. I looked at the diodes and didn't see anything odd, but will look again.
That smell doesn't go away. If the cover is on, it holds that smell. The diodes, they have to be checked individually. A cheap harbor freight meter is enough to check them. Just make sure to put them in exactly as removed. Will post schematic when time permits
What is the fuse blows identification.
RE3101=15A RE3102=15B FC03=20A fuse in or near battery or battery switch. Hope this all helps
Thanks. I look another look/smell and nothing at all. However the cover was off for a few days, and I had the cover off when the issue first popped up a few months ago so I wouldn't take it to mean anything. I attached a picture I don't see anything out of place. Maybe a dumb question but what am I checking with the diodes with the meter, resistance?
You check them with the diode check function. It will show open circuit in one direction and a low voltage reading when checking the other way. You are focusing on DI10,11,3606 &3607 which are not shown as far as location, not in the fuse panel. Good luck on the hunt.
Thank you. I see the first two, but where would 3606 and 3607 be located? Don't think I will get to this tomorrow, suppose to be almost 0F with the windshield tomorrow way too cold to be working on electrical...... Definitely need to get the heater working before my next job with this thing thankfully i've got another week.
Checks the resistance of all 8, lowest is 4.2 highest is 6.3, most were in the high 5s?
That's all good. Open circuit when checking in opposite direction, right?
Yes if I did it right. In the same mode I got no reading on any of them the opposite way.
Is there more fuses etc somewhere else? I took out all plastic cover behind seat didn’t find any, above the battery box there’s just the boxes and main breakers but I’d think there would be a lot more problems is one of those was gone? When I turn the ac/heat on and change mode I hear a click but that’s it. Has to just be fuse or something burnt out that just controls all those things. Is by chance everything not working 12v and could be the convertor?
Have you checked for power at the blower? It's a real pain in the @$$ to get at. The resistor has been known to crap out from time to time.
No I haven’t. My hunch is all these things blower, radio, Espar, wipers stopped working at the same time so I can’t think it’s likely to be anything actually wrong with them, other then them not getting power from fuse or whatnot being gone.
You hear relays, you hear blend door motors, you see functions on control panel. My guess is blower or resistor failure. Going by your logic is what prompted me to suggest checking diodes and circuit board in fuse panel. Those are your weak links. I think at this point, you're committed to checking the resistor. Winter is hear after all.
Yea it couldn’t hurt. Where is it located? I don’t think it’s the blend doors, as when changing vents on screen nothing happens. I think it’s the recirculating button that made the click?
Behind the seat on the floor. Its load of fun.
For the relays I wasn’t able to test 3701, 3702, 3101, 3102 as there is no others ones to swap with, is there any chance they could be it?
Yea sounds like it. Is it easier to remove seat or try to do with it in?
Taking the seat out is a major undertaking. If you're small enough, I'd struggle with it. If you're 6'2" @210 , then I'd definitely pull the seat. take lots of pics. Itll help going back together. Dont try to take the riser, then you will be disturbing half the electrical system in the cab.
Awesome. I'm 6'5" about 290 so that's not going to be fun if I have to do that.
I pulled the 4 relays in the top right corner again as I want to be sure they aren't it first. All 4 have about 0.324 resistance across the 2 side poles. The two 5 pin relays for the ex1 and ex2 have 0.00 resistance from poles 30 to 85. Infinite on all other combinations. From what I was reading all of them have way too little resistance and would mean they are bad?
85 to 86 should have continuity. 30 to 87 should only have continuity when 85 is powered and 86 grounded. That pulls 30 down to contact 87.
I didn't connect to power at all.
You wouldn't, not using an ohmmeter. EX1&2 AKA 15A & 15B are the heavier relays with 2x¼ pins and 2x5/16 pins.
All clicked fine when power was put to them. 3/4 had 0 resistance, one had infinite. It was either 3102 or 3101. But I am sure I swapped them before and no change?
Forget that, I went and re-tested all again, all show 0 resistance. So all 4 relays must be fine? I am going to try the heater thing, but my thing is, it won't fix the radio, espar, or wipers all of which died at the same time. I am satisfied that everything in the fuse box behind cab has to be good. But above the battery box I don't know. I took apart and looked everything, but no idea how I could go about testing any of it? Like those 2 breakers? I think 1 box is a converter?
Called the dealer and they suggested checking the breakers above battery box. The two big ones were good. But the little 15 amp on the side, I got nothing on one side and my test light when green indicating ground on other side? Aside from them being the problem they said it's likely a shorted wire between battery box and cab, would anyone happen to have a schematic of the wiring to be able to tell what wires are for the things i'm having issues with? The only other thing I could possibly think of is there is 3 sensor type plugs in the battery box that I have no idea what they are for? But I can't see them affecting the things i'm having issues with?
Have you checked fuse FC03 at master switch. That would be your battery keep alive for your radio, I can't remember where it is exactly. I suspect that is what you've found. See schematics posted earlier.
I haven’t seen a 20 amp. The one on the side I was referring to is 15, but who knows if someone changed it at some point? Then there was the main 150 and 80 breaker I believe. The only other fuse I found near battery box was inside the silver box, not sure what it is?
I guess to verify it’s fc03 it should be the only thing with power with disconnect off right?
Yes, that would be it. And that should power your 24/12 voltage reducer to run your radio. You've mentioned ESPAR a couple times, I don't know what that is, can't seem to find it in service material either. What does that do?
I checked that 15 amp fuse again, no change whether disconnect is on or off. But my tester is showing green indicating ground, all other hots show red. I had the other side of tester grounded to battery if it makes a difference. Nothing on the other side of the fuse. Now my thinking is if it's a fuse it's gotta be power and it must be the 20 and a 15 put in mistake, and because it's showing ground wouldn't that mean somewhere the wire is broken/bare to the machine and this very well could be my problem? It was way too cold out to start taking the loom off and checking the wire so didn't do anymore then that. Espar is the diesel coolant heater for cold weather starting, I believe it was in mine right from the factory. It is located right below the radio.
My plan to test was to run a jumper from the battery to the other side of that fuse, then I will know if that is the problem. My only concern is bypassing the fuse would I risk sending too much power through?
Not if you put a fuse in the jumper wire.
Well tried the jumper, no change. Anyone know location of where that wire goes so I could trace it for damage, or better yet test other end to see if it’s damaged somewhere? Also assuming this fuse must control the things I’m having issues with and not just be a coincidence that it’s showing grounded?
Bump anyone happen to have any other ideas, or wiring diagrams for the machine? Can't find any online. I am going to trace that wire that I think is likely fc03 and see where it takes me but if it's not that then I don't know where else to look. It does seem likely that it's the problem, but other ideas if it's not would be great. I was going to take it to dealer but it's too late, got a job to start on thursday. The espar is by far my biggest concern, if it turns cold i'm stuck plugging it in with a generator to get it going. I don't remember for sure, but I do believe the espar still had power even with the kill switch off, so it should be powered though the fuse that always has power? I haven't checked the heater itself, while it would be nice it's not top priority.
So, have you checked the heater motor for power?
Not yet considering how time consuming it is to do and that it's not as important as the Espar. I can get by with an electric heater or whatever if I have to, but I really need the Espar working. And I really have to still think that all these things are connected, or at least some of them. Do you happen to have more wiring diagrams of the machine like sch11 where fc03 goes to?
Fair enough. I found your Espar except its eberspracher . Power leaves FC3 in schematic 1 off to schematic 11 feeding fuse FU20 to power CU8702 which is your control timer for the diesel heater. You can also see the relationship of RE8701 to control the heater unit HE8701
Thank you so much. If i'm reading that right, fc03 controls hvac power relay, espar, and the radio? There is no way that is a coincidence that all 3 of those aren't working, the problem has to be in that line somewhere.
Could I not test by putting a jumper wire to pole 30 of relay 8701, with a inline 20 amp fuse of course, then test hvac? And then run a jumper to fc03 and test for power at fc20? That would test the run between the two to tell me if there is a problem, or I could test the continuity of that line?
Not a fan of jumpers and bypasses. Much better to find the damage and correct. Your machine, it's up to you. I know the weather is bad and ya gotta do what ya gotta do.
Not to actually use the machine, just for a quick test to see if it's the problem. I just don't want to mess anything up bypassing or putting power where it could damage something, even if just for a moment so wanted confirmation my test would be ok?
Yes, fused power to 30 cavity will not harm. It may actually backfeed other circuits. I would check for voltage there prior to jumping. Good luck
It works! With fused power to fu20 the heater and espar work. No radio and no change in wipers, wipers still blows fuse as soon as you turn them on. My thought was cut wire at battery box just after fuse then outside of fuse box and run new wire, I shouldn’t have to worry about the old one if it’s cut at both ends I’m guessing the wire melted the shielding at some point and grounded out?
Disconnect your 24/12 voltage reducer. They have a tendency to short Out.. see if that doesn't help
Which thing would that be? I know its above battery box.
With a jumper wire to fu25 the radio works now.
Well, you've eliminated the 24/12 as a suspect. No need to chase that.
I got the power directly off of the battery disconnect so I bypassed the reducer and wouldn't know if it's bad right? Where would be the place to start on the wipers? What would it mean that the fuse is fine, until I go to turn them on?
That the wiper motor has failed or the wiring is shorted.
If I try to use wiper or sprayer it blows instantly makes no difference, i'm just trying to figure out what section of the wiring it might be? They are separate switches so I guess it's possible both got fried (both working fine before battery issue) but i'm guessing it's some main connection to both? Am I correct to assume that because it only blows when I turn the switch on it must be the switch itself or wiring from the switch to the wipers? And from the fuse box to the switch would be fine?
Start by disconnecting wiper motors, upper and lower. Try switches, does fuse blow? If it doesn't, figure which one fails the fuse. Plug one in, and try. Plug the other and try. If the fuse failed with the motors unplugged, look at CU3601. That is your timer relay. That controls delay and high speed. If fuse still fails w/ CU3601. Considering that CU3601 is above the battery box and that's where your 'event' took place , odds are the problem is there.
Did a more testing wanted to check if it was the convertor or wiring that was the espar radio and heater issue. Tested the wire between convertor and fuse box all good. Opened the convertor and found this. I’m going to make the assumption the black stuff is from something blown and it’s garbage? Any guess what it’s going to set me back to replace? If its insane could I just buy a generic voltage convertor or is there something special about it?
Here’s photo
Those black blobs are isolators. They kinda keep stuff from bouncing and shaking loose. Does anything smell burnt? Is the fuse in tact? With the consumers (wiper motors) unplugged does the fuse continue to fail?
Oh. I thought that when I opened it before, but now just assumed it had to be it. The fuse inside isn’t blown but it won’t come out. Smells fine. Tried to take a picture looks like fuse melted a bit maybe? The wipers make the specific wiper fuse fail, but not the one in the convertor which is still good.
Found something strange. When I test continuity between the wire at convertor to the 20 amp fuse fc03 that is the same wire that has power? Well my test light goes green on it? Going to pull off loom and trace those wires but shouldn’t that mean those two wires are touching somewhere?
Well I figured it out, tracing the wire it was taped off. Works perfect with power hooked up to it. Thank you so much for the help and patience funwithfuel I would have spent a fortune paying someone to fix it otherwise. Still need to figure out the wipers here but that’s minor.
That's fine cuz FC03 feeds that 24/12 converter . That's why its important to have properly rated fuses in the correct locations. Its looking like one of the wiper motors has failed. Glad to hear things are looking up
I'm going to look into the wipers at christmas when I got more time, no rush. It's a PIA doing all this while the hoe is on the trailer at christmas i'll have time to put it inside and fix all the little things. It also reminded me that my Espar randomly likes to throw a code and not start. Since there is no trace of where the wire went before, what would be the best way to tap into power for convertor? Obviously it needs to be before the shut off, should I just tie in right where power comes to that? Also probably a odd question is there some trick to replacing the crankcase filter? I remember trying before and not being sure how it was done.
There really is no crankcase filter. It's just a valve in the back of the valve cover that maintains pressure, condenses oil out of vapor and dumps it back to crankcase. Vapors typically get pulled into turbo for consumption.
Might still be something wrong but hoping not. I've been running small truck batteries since the fire, and I went and bought 2 4D's to get it back to what it should be. Ran machine yesterday for probably 30 mins, everything good. Delivered it to job tonight and once I idled it up within a 4 clicks of WOT it came up high voltage warning. Shut it down looked at everything everythings fine. Did it again once I got within 4 clicks of WOT, but if I kept it under that it was fine. Once I got it on the lot I put it WOT and moved controls, etc a bit and no more warning? I'm wondering if maybe the new batteries caused it by being a lot bigger and the system thinking something was wrong? I know with the smaller batteries on a really cold day once it fired up it would do low voltage warning for a bit, assuming because it drew so much power getting it going.
You're gonna see low voltage warnings for a bit on cold start up. The preheat relay kicks in for a bit on n off to control smoke and help her keep running smoothly. Voltage high means your voltage is above 30 volts. Dangerous voltage for ECUs . Check your power lead at the alternator .
Ok what am I looking for when i'm checking it? Testing it for something? As long as that warning isn't coming on, am I safe to run it? I had to run back and move hoe just now and it didn't come on.
Safe as long as you're below 30v. You will usually see 28 or so.
I figure I should double check. This little black and red wire in my picture was hooked up with previous batteries but I didn’t rehook it up, should I have? It looks like just a plug in but it’s been so long can’t remember.
Ok. And the warning light comes on at 30v?
I believe so, it might be as low as 29.5. Its telling you that you're in the not good zone. You'll start overheating diodes and cooking batteries. Make sure all the cells in those new batteries are full. Keep vigilant and you'll be fine.
Well still a problem. If I run machine past 1600 rpm and do much the voltage jumps up and warning comes on. Even at 1600 if it starts to work it comes on. But 1 more click down and doesn’t come on, and keeping a eye on voltage is doesn’t change at all. I checked battery cells looks like about 1.5” down there is fluid in them? What else should I be checking?
So your display continues to show ~28 volts and the light is coming on, I guess you might have diode leakage. If you measure from alt output post to chassis ground on A/C scale, you should show no volts, if you have A/C voltage, odds are the rectifier is failing.
1600 is fine for bucket, but if I so much as touch the tracks (while doing nothing else) it spikes voltage??
You shouldn't run in F3 for prolonged periods. It defaults to powerman, so your pump is really working harder as hard as that is to believe. What is your static battery voltage.
I only use briefly when warming up, and just noticed voltage seemed to be worse with higher rpms. This is where it sits at idle
Done with the machine until the new year so wanted to get the rest of this fixed. Operates perfectly fine up to WOT for everything but the tracks. If I so much as touch the tracks at or above 1600 RPM's (the cut off for the strongman) the voltage instantly spikes to around 40, and you can hear the engine change noticeably too. But it's perfectly fine for everything else? It's seems so odd.
Still trying to figure out issue. Either it happened by coincidence when I was working on other things, or it was swapping something maybe? The only thing I could think of would be some of the diodes got swapped and a bad one ended up where it has something to do with the tracks causing the issue? I disconnected the wire for heater/espar thinking maybe somewhere else it got damaged causing the issue and fixing it at one point maybe caused the issue in another spot, but made no difference. Dealer had idea of maybe the strongman being on gets rid of issue for some reason, so I tried turning on strongman at higher rpm, doesn't change problem still there. Dealer didn't have any other ideas other then a shorted wire somewhere for the tracks. But something that only causes the problem with strongman not on.