engine

rics83 · October 19, 2004

I have an 82 GMC truck 1500 with a brand new crate motor and new tranny. Problem is that when the truck is in park or neutral, the alternator is charging fine at idle or high rpms, as soon as it's in reverse, drive, or the lower gears, the alternator quits charging, headlights shut off, and the truck runs on the battery but only when the engine is operating higher than idle. As soon as it's back to idle, everything starts working again. I've changed the battery and the alternator numerous times, only to find out it's neither one. It's something else, only thing is, I don't know what. If anybody knows what the hell i'm talking about, please let me know. I'd definitely appreciate it.

millerwd · October 19, 2004

Ric, did this start after the motor upgrade or the transmission upgrade? Without an electrical schematic it;s goeing to be hard to troubleshoot.

But my first guess would be a faulty relay somewhere, since you haven't burned up the alternator it doesn't appear to be a dead short.

Have you checked to see that all fuses are in and not blown?

I'm not sure if this site will have diagrams going back that far.

http://www.gmupfitter.com/

rics83 · October 20, 2004

Ric, did this start after the motor upgrade or the transmission upgrade? Without an electrical schematic it;s goeing to be hard to troubleshoot.

But my first guess would be a faulty relay somewhere, since you haven't burned up the alternator it doesn't appear to be a dead short.

Have you checked to see that all fuses are in and not blown?

I'm not sure if this site will have diagrams going back that far.

http://www.gmupfitter.com/

<{POST_SNAPBACK}>

I have checked all fuses and removed, cleaned, and reinstalled all grounds. I bought the truck with the up grade in it and I have been having electrical problems since. The guy I bought it from can't offer a whole lot of help either. Thank you for your reply