Heavy Equipment Forums Heavy Equipment Community

Case 580 CK generator warm even before starting

TSemenuk ยท 2020-08-17 19:11

I rebuilt the fuel pump and put it all back together today. I cranked it a half dozen times to get fuel to the injectors. I walked around the tractor before it started and by chance put my hand on the generator and it was quite warm. Not too hot to touch but very warm. Wondering why. Some background that might be related. I removed the starter to bar the engine over to time the fuel pump and the end cap on the starter solenoid broke into 4 pieces. I was able to epoxy it back together and the starter works as it should. Do I have voltage going back to generator from the battery through the starter?

Replies9
  1. #1franklin22020-08-17 20:39

    Does this have the GM alternator with a #1 and #2 cast in the back near the small plug with the smaller wires? If it does, make sure you do not have voltage on #1 unless the key is in run. This brings the alternator online to charge. It will run the battery down if this wire is hot all the time. If that checks ok, you may have a bad diode in the alternator. You can take the battery negative wire off the battery, and then clip a testlight to the battery terminal, and lay the cable end on a rag and put the sharp part of the testlight onto the cable end. If the testlight lights up, you have a constant drain (with the key off). You can then take the heavier wire off the alternator, if the light goes out, you have a shorted diode inside the alternator.

  2. #2TSemenuk2020-08-18 07:33

    Franklin, it has the original two-wire generator. The wire at the terminal with "A" stamped in the generator body has 4 volts when the key is turned to the "On" position.

  3. #3Tinkerer2020-08-18 08:00

    Yes voltage is being applied to the generator. You most likely have a defective voltage regulator with stuck contacts. When that happens the generator is actually a dc motor that cannot turn because the fan belt and motor keeps it from turning. It will probably kill the battery unless the contacts pop open. IMHO !

  4. #4TSemenuk2020-08-18 09:11

    So I can check this by loosening the fan belt and turning the key on to see if the generator turns with the voltage?

  5. #5Tinkerer2020-08-18 09:18

    Yes, you can. I would put a GM alternator-one wire conversion on the tractor before I spent any money on the regulator. It would be my luck to buy a regulator and then have the generator fail.

  6. #6TSemenuk2020-08-18 09:28

    Do you know of a good instructional resource for the alternator conversion?

  7. #7Tinkerer2020-08-18 13:11

    Yes I do ! Right here at HEF. It has been discussed many times. Here is a link to one of the many threads about it. Check it out and come back and you will get all the info. you need. HeavyEquipmentForums You can do a Google search for-- GM one wire alternator conversion-- and get endless information about it also.

  8. #8TSemenuk2020-08-25 06:15

    Yes Tinkerer, the generator is turning backwards when the ignition is turned on. Some regulator maintenance is required. Who knows how long that has been fighting against the starter slowing down the cranking?

  9. #9Tinkerer2020-08-25 07:19

    Glad you have it sorted out ! Mystery solved. Now all you need to do is fix it one way or another.