Alternator hot to touch

[laserfish]

While I was replacing my harmonic balancer that decided to become two separate pieces yesterday, my arm touched the alternator pulley. As the engine had not been run for over 24 hours, it startled me that the pulley was hot. The entire alternator case was hot. I disconnected the hot wire just to be safe. It is a G3 130 amp alternator that has been installed since around 2006. What could be causing this?? Also, if someone has one, a wiring diagram to be sure it is wired correctly (even though it has worked since installed). Thanks guys.

 

[Steve83]

Sounds like some burned diodes - I've had 2 alts burn out on me in the past couple of months (on my '94CV & my '83B). This shows the eB wiring for a 3G, and the caption contains more relevant links:


(phone app link)

 

[DirtDonk]

And the key was not ON at this time, correct? Just checking.
Also check your battery voltage. With the alternator hot like that, it should have been drawing a bit of power to say the least. If it had only been tweaking like that for a couple of hours, maybe your battery was ok. But much more than that, and it should be showing signs of being drained.

Before replacing the alternator, make sure there is no power on the Green w/red wire with the key OFF. Or in ACC for that matter.

Paul

 

[laserfish]

Well Paul, you nailed it. When I was bumping the starter to get the crank keyway at the top, I left the key on. Not a bad time to check everything though. Just glad it was not something major.