Alternator

[brentb]

i have a battery drain short on my case 1370. I tested the short with a meter and soon as i unplugged the alternator the short was gone.I replaced the alternator and re tested again and it seems as though I still have the same problem. If I plug the alternator in I can still see a short. Unplug the alternator and the short is gone. i dont know if I am doing this right or not. Any ideas. The short will drain two brand new batteries in about 7 days.

 

[farmboyWI]

Somebody correct me if I’m wrong, but that sounds like it could be a bad key switch. Try unplugging one wire at a time from the alternator and see which one makes the difference.

 

[AllanC]

Usually if the alternator is killing it, it is a bad diode in the alternator. But a rebuilt doing the same thing?? which plug are you unplugging, the regulator plug (the 2 wires together) or the main (big)wire.

 

[brentb]

I was unplugging the 2 wire plug that goes to the regulator. I guess it is feeding the rest of the tractor from there. I dont have a wiring diagram

 

[Anonymous-0]

if this is a 10si Delco the threaded post is live all the time and the plug in wires are keyed power so if you have power on the key switched wire then you have another problem like a bad switch or two wires making contact, are you checking for a short with a test light between the ground cable and the batt post?

 

[brentb]

I can see the short with a volt ohm meter and a test light either 1. I remove the neg. terminal from the battery and hook up from the battery to the neg. terminal and it is shorted with the 2 wire plug plugged into the alternator. My alternator has 1 hot wire from the harness always hot and a jumper over to the 2 wire plug into the regulator