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650H won’t start

Alan Caro · 2022-12-05 17:31

I have a 2004 650H that when you try to start it, it seems to cut power to the system, I checked if the powershutoff was the problem by jumping both negative cables on the same side and it stayed the same I also checked the negative cable for conductivity and it seemed to be working fine any ideas on what I should check next?

Replies9
  1. #1Alan Caro2022-12-05 17:46

    More info: The problem begun slowly as it became more progressive, sometimes after a few tries it would start and continue to start other times we jump started it and it would start and continue to start without the jump starter in normal condition we checked the battery connections twice and they all are fine

  2. #2BillG2022-12-05 18:10

    Under the hood on the left side, behind the dash is a series of relays. I don't have a diagram in front of me but pull each one and check the contacts. they can corrode over time. Clean them up and retry, put a little dielectric grease on each one. If you can check each relay while it is out.

  3. #3Alan Caro2022-12-05 18:14

    Ok hopefully tomorrow if I have the chance I will check those, is there a possibility for it to be the thermostat sensor too? I saw that on some john deere tractors the thermostat sensor gets bad and it does the same thing

  4. #4BillG2022-12-05 18:17

    No, this is just a basic tractor. The only electronics are the dash monitors and they don't prevent a 650H from cranking and starting.

  5. #5Diesel Dave2022-12-06 14:57

    If the relays prove ok, I would suspect poor main power connection at the starter terminal or defective key switch.

  6. #6Simon C2022-12-06 18:25

    Could you have a defective cable halfway through. Have done voltage drop testing to find one on a John Deere Powered Screw compressor with only 50 hours on it. The cable was cut off internally and could carry no load, but unit in warm shop could start with big battery pack boost. something to check carefully. Simon C

  7. #7bobatack2022-12-06 18:50

    just another bad connection tale Just last week I was out helping one of my friends on his place They tried getting the skid loader started with no luck It would preheat without an issue but when turning key to start it only turned the engine about 1 round and kicked out with seemingly low battery So we tried boost starting it with same effects I got looking around in the engine compartment and notice this main kill switch Oh ok i just switched it off and on few times (not really knowing it would do anything) Told guy to try again and bingo starts like nothing was wrong So just a wild guess but there must have been poor connection in the kill switch

  8. #8Alan Caro2022-12-14 13:40

    Hello! Had some time to work on it, I checked the wiring with the power probe and noticed that there were 12V going into the starter relay and 9.0V going out of it, decided to go ahead and replace it and it has worked properly since then, might have been lucky there.

  9. #9Alan Caro2022-12-14 13:41

    Thanks for the help!