Hot Alternator

[dwsatt21]

Anyone have their alternator get very hot without the car running. My was just sitting with the batter connected to a charger/tender. I went to mess around with my coolant over and bumped against it. It was almost hot enough to burn me.
I was thinking it may be a grounding issue but there is barely any resistance between the cats and the frame.

 

[choppedtop]

Had that happen about a month ago. Exciter wire was hot all the time. It had to be run from a switched source such as the ignition switch. May not be your problem, but that is what cured mine. It was on friends new ride.

 

[dwsatt21]

Thanks. I’ll check that out.

 

[dwsatt21]

Yep. 12.8 volts with the ignition switch off. Thanks for the help choppedtop!

 

[dwsatt21]

I haven’t fixed it yet but ever since I unplugged my alternator exciter wire, it’s not getting hot anymore. The harness I have has two alternator wires and not very clear directions. One is called alternator power and the other alternator exciter. The directions led me to hook up the alternator power which is apparently hot all the time. The alternator exciter is only hot with the key.

 

[choppedtop]

Looks like you found the problem. The keyed one is the one you want to use.