T300 that will drain battery after sitting and will not fire up start engine panel in cab. So, New battery, it started for a few days then same deal, it discharges battery over couple days. checked alternator, its good, ( pulled and took to shop to make sure ) took new battery back to napa, it checks good. what is weird, is even with a fully charged battery now , it will not light start panel located in cab up so I can start it, but if I hook just a little battery charger up , 6a amp for 10 seconds, it will light panel up and start engine. Im getting 12.8 volts at starter, almost 14 with 6 v charger hooked up. I ve swapped out relays and checked all fuses in panel in cab. alternator is showing charging good while running so, something is robbing voltage from battery to panel used to start the engine in cab, and also draining battery while not in use. after it runs a while , it charges the battery enough it will shut off and restart without the charger being on it, but if it sits overnight it draws battery back down so have to have boost or use charger appreciate any help,
Hook up an ammeter and start pulling fuses. See is you can narrow it down some.
That doesn't sound at all like a drained battery to me. More like a loose connection somewhere that you're moving when you attach the charger? or the panel needs more than 13V to start up? or something else, but not a drained battery if it starts right up with ten seconds of low charge. Usually a low battery will have enough juice to turn the lights on, but then crank too slow to start, or just click and not crank at all. need to spend more time with a voltmeter to see what's going on.
Sounds like a corrosion problem in your battery cables maybe.
I dont have one, but Ill get one or get someone to help. Im not much on elec circuits, always detested working on them
thats been checked, and voltage does not lower from battery to starter when checked
battery will not fire up anything, lights, control panels , radio. the system has to come on by control panel before anything will work when left connected for couple days, battery is dead. ( less than 10 volts) and battery has been checked and new not a loose connection at battery or would not show 12.8 at starter lead the battery is fully charged, (12.8 v) and still will not light up the control panel that starts engine, unless a little boost is added by the charger ( shows almost 14 v at starter on the harbor freight battery meter i have)
possible, but not its not at battery or alternator or starter,,, im thinking a loose connection somewhere between battery and contol panel inside, just not sure where to look.
OK, I didn't realize there were two problems, the battery dying and the display not lighting up. Could be the same problem? two symptoms. Like if the display is hooked up live and draws a little current for a bit on shutdown, then a loose connection keeps it starting up and shutting down over and over? If you're not good with a volt meter, then a power probe will be cheaper than a service call. It won't find anything for you, but it will make it much simpler to hook stuff up and test, so you'll be able to think about what's going on with the electricity instead of just figuring out a rat's nest of test wires.
You don't have to have an ammeter to find a drain, disconnect your - battery cable, put one lead of voltmeter on cable and one on battery. If it shows voltage, you have a drain. Pull fuses until it goes away. If you use a digital volt meter, you will probably never get to 0, but if you get the voltage to drop, you found it.
Any good auto mechanic can test it for you if you can't find a heavy duty to diagnose it for you. Maybe you have cables that are beginning to fail also. I just did a car that was sucking down the battery, in the end it was a radio grounding out inside. Found it with a multimeter as " mitch504" said. Find a competent mechanic and in a short time you will have it solved. Simon C
so we put a voltmeter , hot lead , post to cable end. turned it to 10 amp, and it shows 0 . used a test light also. so , not showing any leakage is what i undertand. put cables on afte looking for a rubbed wire , started right up. turned off and the start panel would not activate again. im beginning to lean toward a faulty control panel , or loose lead or short in it.
The multimeter has to be in DC Amps mode with the black test lead in the neg. com, and the red test lead needs to be moved to the 10 amp com., with the rotary switch in DC amps. Then the negative cable is disconnected and the positive red test lead touches the cable end, the black test lead is touching the dead center of the negative battery post. If something is sucking down your battery it will have to pass through the meter and will appear in amps on your meter. Then when you pull the fuses 1 at a time the fuse circuit sucking the power will drop the reading on the multimeter when it is pulled.. Hope this helps. Simon C
You can do it the way Simon says, (fun game), which is using an ammeter, or, to do it the way I said turn it to DC VOLTS, which is using a voltmeter. The tool is called a multimeter, it can be a voltmeter, ammeter, ohmmeter, or other things, depending on the model. I gave you VOLTmeter instructions since many of them don't have an amps setting. I personally use the volt method for parasitic drains, even though I have an ammeter. It has finer resolution on my meter. It sounds like you may have an intermittent drain, which may or may not be related to the other problem, but probably is.
UPDATE i've decided that battery drain may not be an issue with the new battery, I assumed it was because I would have to hook a charger to battery to light up the run panel so it would start. previous battery would leak down, but it did show a weak cell. Ive checked voltage for 2 days and it has not lowered while hooked up. AND 1- I've checked all fuses with control panel active, ( light up) they show 12.8 volts. 2- control panel shows 12.8 v on pin that feeds the run button, and I'm using the black wire as ground, so I assume that everything is grounded until it reaches the control panel. what the CRAZY thing is, I can put a 6 amp charger on battery for 5 seconds and the control panel will allow the run button to light the panel up, why does this extra current , maybe 2 volts, allow this to energize, so that machine can be started?????. maybe its the contol panel button i never could figure out how to edit the original post with this update:
Ive talked with a past bobcat mechanic and he thinks it prob the control brain , OR hopefully a weak connection between the operation panel inside machine to the control brain. he explained the operation panel inside cab , only sends signal to brain. I took it to bobcat 2 years ago , with another issue and they installed a new control brain in it, and thought that was the problem, and it was not. so the brain is only 2 yrs old.
I would be checking and cleaning all the connections I could find, particularly the grounds.
You can't edit a post after one hour. It's better not to confuse the readers, we are easily confused. I'm not understanding post #15, did you first connect the charger to get the panel to light up? I'd think you need to check voltages when the control panel is NOT lighting up. And that includes grounds, so checking fuses to the battery - neg terminal, but also then checking the panel hot to the ground that the panel is seeing, so it's case or it's ground terminal.
its easy for me to confuse folks, Ive always had a short between seat and keyboard. Yes, I have to connect charger to key pad to light it up, just 6 amp for 5 seconds will do the trick. once its lit up, I've checked all fuses , they all show 12.8 v. the keypad is getting 12.8 volts using the hot lead and keypad ground, and yes the panel was off when checked. i only checked fuses when keypad was lit up. all grounds in back of machine have been double checked, including the 3 on top of neg post. Ive called a mobile mechanic, independent that has done it for years, hes worked on a lot of t300s and 250s. maybe he can trace the problem, just maybe its something simple.
Start with a simple voltage drop test of the positive battery post dead center to the positve of the starter. Check voltage drop on negative cable from Starter to Negaive Battery post dead center. This will totally eliminate a broken cable internally. If the mechanic has never done these tests shop elsewhere. Both tests have to be done while attempting a start to run current through the cables. Would be good to test from Frame ground to Dead Center of negative post of battery to eliminate faulty frame ground cable. Good to test from Dead Center of Positive battery to Battery connection of Fuse panel and also dash power. Please let us know what you find as we can possibly help. Simon C
Do what Simon says (I'll spare you the joke this time), and if that doesn't find it, I bet you have a relay that is failing, and needs the extra surge of power to latch.... maybe.
Still thinking ^^
Checking voltage at control panel plug will not tell you if the wiring can carry any load. I would use a test light to check power and grounds. That will verify that you are getting some continuity through the harness. A dim light or checking for volt drop when probing with test light will lead you to the problem.
A multimeter testing from the positive of the battery to the positive of the fuse panel while under load will tell you if you have a weak connection to the fuse panel, but will not tell you if there is a weak connection to the remaining wiring harness of the machine after the fuse panel. A test light as ( 63 caveman ) said can put some load to the other circuits to test them. Test light also good for testing fuses. Hope you find the weak connection. Simon C
just as a follow up, finally got a independent mobile mechanic out, he could not find any issues with grounds anywhere. He called a contact who is a bobcat mechanic at dealer, neither one had ever seen a situation like this. machine still will not light the panel up so it can start without a small boost, just 6 amps on charger for 5 seconds will work. common sense suggests a ground issue, but none found. all testing's shows current with ground to control panel in cab. they think some issue with control board, which is requiring it to have a little extra voltage or amps to allow it to send signal back to panel in cab that allows it to start and run next step is to send ecm off for testing.
Might be wrong, but if even a small boost starts it up, that is suggesting that there is insufficient voltage to the panel or computer. Those circuits need to be tested while trying to start and under load. The grounds out of those connections also need to be tested under. First test done that shows a voltage loss of 750 mv., would be way too much on the positive side. Should not be very high on the ground sides. If your starter is actually a little loose it will start with a boost but not on its own because the charger provides a new path to ground. I found one like this on a logging piece of equipment that would only start with a boost. Hopefully you have some recording meters to do the testing that I suggested in a previous post. i personally use 2 Fluke 87V meters at same time to rule out errors. Simon
this one has a Run panel in cab, what is happening is the run panel will not light up when pushed, which allows the start button to be pushed to start motor I have 12.8 v at that panel, testing while using the ground supplied to that panel, so its either how it communicates with other panel, (top left in cab) or ecm. All this is beyond my pay grade to be honest. I can spend $100 and have the ecm tested by sending off. the mobile i had come is a good general mechanic that works on everything, and we checked all grounds, and he tested all power to most components except ecm. we did have one success , as i was wiggling one ground lead coming to battery post ( 3 screw on top of ground lead at battery ) the machine did light up , actually did it 3 times in a row. we thought we had found the issue and he took a punch and reset the clamp. we never could duplicate the results again. Im going to cut them off today and take a pair of vise grips and connect them to battery and see if it does it again before i send ecm off. he did check omhs ?? on main ground leads and nothing showed. we thought lead may be corroded inside and not visible.
I still think it’s a corroded connector somewhere
Just a thought. . . Is your charger clamp helping to "fix" the weak connection? Possibly in the main negative cable at the battery, I've seen a number of those fail internally at the battery terminal. Being as you had some success wiggling that connector a new negative cable might be in order.
Had two top post cable clamps cracked from over tightening recently. Would want to find the reason wiggling the ground wire lit up the panel before sending ECM off. Start at battery and work down the wire make sure all connections are clean and tight. Flex cables gently looking for a place where wire hinges instead of bending and signs of swelling and or green corrosion.
An ohms test will be good if even only 1 strand is still connected from battery end to ground end. Will it run anything, absolutely not. Both test leads of meter have to be on same cable while trying to start, with the meter on DC Volts. If it indicates even 0.5 V from the dead center of the negative battery post to the starter ground stud, you have too much voltage loss. On the positive side one meter terminal stabbing the dead center of positive battery post and the other lead stabbing the center of starter solenoid while holding the starter on will read less than 0.5 volts or 500 millivolts (same thing). These tests need to be done to verify 2 good battery cables. A single booster cable from positive to positive, or from negative to negative will tell you something is bad in the cables if anything starts to work. Hope this helps. Simon C
Thanks simon, So I did send the ecm off, it does have cracks around edges on 3 sides. But, isoscell has emailed and said it is good. so, if I understand correctly , the ohms tests he did , are not really accurate unless it is trying to start?? which it will not do, unless run panel in cab is activated. ( its does start , once that panel is activated. its getting the run panel to activate that is the issue, located in cab) but you have suggested , ( i think) 1- take a booster cable from positive lug on battery , to starter solenoid and see if it will light run panel up 2- then take a booster cable and go from neg lug on battery to frame and ground and see if it will light run panel up ? 3, and then maybe do both sides at same time, ( steps 1 and 2 together) so, we are down to, possibly or maybe I just hoping! 1- its a bad ground or positive battery lead connection, with internal issues not visible. or 2- its possible the run button on controller in cab is not getting enough contact without some extra voltage/amps Since I am showing 12.8 v to that controller in cab , using the black ground lead that supplies it . ( the red and black supply wires) If that be the case , then the wires on battery should not be an issue????
Might check your battery terminals first. Sometimes when you place jumpers or charge clamps on the terminals it will pinch the clamp and correct a slop situation
yes, they been double checked by me and another guy,
Have you checked if the voltage stays at 12.8 while you press the button that is not working?
I have not, the panel will not light up and activate the buttons, so I didnt think it would do any good. should i try that with the panel not lit up? press the run button even tho its not activated?
Power could be possibly not getting to button, or not exitting buton when you push it. Just a couple extra small tests to do. Love to help, but when not there can just ask if you tried this or that. Simon C
Maybe take a good look at the keylesss start panel, either swap or send to Isoscell to test. Those panels can have odd/ intermittent issues. On a side note , we have a customers machine with somewhat similar issues, we tried a test panel and are leaning towards a failed mainframe. So if we could only swap some parts. . .
I really appreciate it, and going to give it a try when the ecm is back in. I'm also going to see if i can figure out which wires feed the other panel , or if the other panel feeds the run panel. a previous bob cat mechanic i know was thinking that the other panel actually fed this one, but he was not sure. if , nothing else happens , ill send both the cab panels off to be tested, id rather do that , than have to move the machine to a dealer ship.
you bet, i thought of someone that has a t300 ( unless he sold it) and ill call him tomorrow, i know he would not mind at all if I did some swapping. it still nags at me that i worked one of the leads that grounds into the top of the ground post , and it allowed it to power up, and it did it 3 times in a row. but then we could never duplicate it again.
That is an indication the wire is broken or damaged inside the insulation. That was one of the more difficult wiring problems I ever encountered. I had another one (battery cable) that had corrosion in it. In excess of two feet in length. It wasn't swollen like they usually are when that happens. It just quit passing enough current allow the needed amps to pass through it.
I would agree with that, but we tried multiple times to make it repeat, and could never duplicate it. reset the crimp, cut it off and put a new one on it, still nothing. wiggle every wire close to it, nope. cussed it, nope actually, we were putting up our tools, after it repeated 3 times. it was a let down.
That's a real bummer. I cannot imagine how frustrating that dam thing must be.
Have you tested for how much power is coming into the dash switch versus how much is going out after you push it. Could that switch have bad contacts. Just asking some simple test questions. Hope you solve it. Simon C
Im going to agree with you, I am thinking a bad contact in the controller, specifically the run button. would make sense, that its weak , but occasionally would work ( since it has before by coincidence ). but never able to duplicate. I got my ecm back yesterday, Im going to try a couple of things and if not successful, Ill take the controllers out and send them for testing also.
hey simon, I got the ecm back in and we did some voltage loss tests today. both neg and positive had the same results. the meter would read 0, when drain was put on by hitting start, the meter would jump to 12 volts, then immediately fall down 20-10 then 0000, it would do all this in 2 seconds or so. i hope we did that correctly. Key pad test procedure; My son did some reading and we went back down and activated the key pad by adding the charger for 15 sec or so, when we did this, he also activated the key pad test at same time. he worked his way thru every button and they all showed active. we also swapped out the relays again, just to make sure. so we have 12.8 v about everywhere we check with machine sitting, with 6 am charger it jumps to 14.8, so just a couple of volts different. takes about 15 seconds and there is enough extra power to activate the key pad, run or enter button. of course it starts every time. if you turn it off, have to put the charger back on for 15 seconds. every thought i have says the battery is not putting out enough amps or a loose connection or ground. we have not found any and battery has been checked twice with load. my last thought is i am taking the fuse or relay panel out tomorrow and make sure there is not a loose or weak connection there.
First make sure your battery is fully charged, then procede with these tests with no charger connected. When you tested the positive cable did you hold the red lead on dead centre of positive post and the negative lead on the positive post of the Solenoid and hold the start button for lets say 5-10 seconds. What was the reading towards the end of the 10 sec. test. Did the starter solenoid go clunk when you turned on that switch at any time up to the 10 second mark. Second test , Touch the Positive lead on the frame somewhere with clean steel and the negative lead on the dead center of the negative post of the battery, While holding the start switch for 5-10 seconds. What kind of number is on the meter at the end of 10 seconds. Third test, Touch the positive lead on the starter itself on one of the securing bolts with no paint and the negative on the dead center of the negative post of battery, While holding the start switch for 10 seconds. What kind of number is on the meter. Fourth test, Touch your Positive lead on the dead center of the Positive post of the Battery while touching the Negative lead on the positive post of Fuse Panel , while holding the start switch for 5-10 seconds. What kind of number is on the meter. Fifth test , Touch your positive lead to the metal part of dash on clean steel and the negative lead on the dead center of the Negative post of battery, while holding the start switch on for 5-10 seconds. What kind of number is on your meter. Sixth test, Touch your positive lead on the dead center of the positive post and your negative lead on the start switch or Start Button ( whatever is on your machine ) While trying to start for 5-10 seconds. What kind of number is on your meter at end of 10 seconds. Seventh Test, Did you hold the positive lead on the dead center of the Positive post of battery , and negative lead on dead center of Negative post of battery while holding the start switch on for 5-10 seconds. What number is on the meter at the end of 10 seconds. Every one of these test is to check a particular part of harness, or possible fusible link or bad fuse connection, or faulty relay harness or faulty solenoid.. Please do them one at a time to eliminate something stupid and simple. Hate to throw money at machines and still no run. When I say dead center of the battery I mean the lead or battery post , not the connector hooked up on it. Take a picture of these questions on your phone then write down the answers on a paper for each one at a time. Post the answers in 0.15 volts or 0.9 volts or 1.9volts or similiar. Want to know what was on the meter. Simon C
I have solved many a no start with these and a few other tests, start with these and then we will move on to further checks. Hopefully we can find problem. You could do test seven before the other tests but need answer as #7. Simon C
Yes, we can do this tomorrow. Keep in mind I cant hold starter down for 10 seconds, it will start right up in 1/2 a second.. Its the run or enter button that will not light up the panel, so that the starter button will work. once it lights up, starting is no issue the run /enter button will not light up, unless a charger is connected. but, i did disconnect the charger , after the panel was was lit up. it has no diff starting , even without the charger. when we did the test earlier today, on both positive and neg batters leads, and starter positive and neg. 1- we put charger on so panel would light up ( run/enter button) 2- disconnected charger. 3- pushed start button, it starts instantly The meter would go to 12.?? very quick and then fall back .10 and then to 0 , all within a couple of seconds, and then stay at zero Starting is not the issue, its getting the run button to light the panel up so that it will allow the start button to operate. It will not light up the panel unless a charger with only 6 amps is hooked up for 15 seconds or so. we did do a panel test, by holding the arrows down as we pressed enter, ( with charger attached of course) he pushed every button and the system says panel is good. Battery is new, i have had it checked with load at 2 diff parts stores.
Problem solved; It turned out to be the control panel run button contact. I sent them off for testing and the contact had some corrosion in it from moisture over the years. Its makes sense that the contact was weak, and it just took couple extra volts to make it kick on to allow the start button to work. thanks for all that helped .
Good to hear!
Just for your information, a voltage drop test with the Red Test Lead on the Positive of the battery with the black test lead to the output side of the push button would of shown a reading of about 1- Max. 12 volts , with the button pushed . Any reading like that immediately tells you something is wrong with the switch. Just for your information for next time. The boost charge was giving enough extra to enable a start. But eventually the switch would of failed totally and nothing would happen. Glad you got it running again. Simon C