I have a 1987 Camaro IROC convertible (LG4 - 305 carb) that's just got a 99 LS1/T56 (99 Trans Am WS6) dropped in. Car is up and running - everything looks good except for the battery isn't charging. I'm getting a P1637 code (generator L terminal circuit) which I can't clear. The harness is from Hawk's.

Any thoughts on chasing this down?

 

Try this link. Scroll down to the diagnostic step section. Hope it helps.

http://www.gearchatter.com/viewpost14190.php

 

Fired it this am and took the RPM past 2500 and the charging circuit came to life. I thought I'd read somewhere that this might be necessary. Does that sound familiar to anyone else?

 

Ive only ever heard of that on the old one wire, self energizing alternators, not on a factory LS alt. Did the code go away and stay off?

 

It has so far, but there are only about 15 minutes of run time on the engine. It is back inside now to button up a few things and probably won't go for a real shakedown until Friday morning. I'll update the thread later on Friday.

One thing that's pretty obvious already - 2.73 rear end has got to go.

 

I used a painless ls1 hot rod harness and it didn't come with an alternator connector, so I ran a fused 12v wire from the ignition switch and it charged the first time, I told my friend to do the same on his rx7 with an ls2 and didn't know that the alternator has to see a ecm signal because signal wire varies from 3-5V and wont charge on 12V, which we just used some resistors to get the 12v to what we needed, I haven't heard of a alternator taking a while to start charging, so I'm not sure what that could have been, just thought I'd share my alternator issue