Hey guys! I'm new to this forum, recently bought an 86 Camaro out of impulse and wasn't a bad decision until i've been having these problems.
So I have an 86 iroc Camaro with the 305 TPI. About a few days before this happened I would notice my car wasn't staying at full battery level by noticing the blinkers starting to get slow. The time it all started to happen I was cleaning the inside for about 25 minutes, didn't leave it idle or anything then I took off and about to get on the highway and it had no power what so ever, ran really rough, battery gauge was way down. I've replaced the alternator and the battery so far but will not stay charging when the car is running. The battery will also die just from sitting there when the car is not on. Anyone have any other ideas to what I can do?

Here she is, the day when I brought it home.

 

I would guess there are 2things going on, first is you have something draing on the battery at all times and you need to check all the circuits to see what one. You can do this with a multi meter at the battery to read the amp draw and then pull one fuse at a time to see what one is drawing too much. Second I would test the trigger wire at the ALT to see if it is getting + signal while the car is running, it is one of the small wires at the ALT plug and it is what tells the ALT that the car is running and to start charging.

here is a good write up on how to find ur drain.

http://www.wikihow.com/Find-a-Parasitic-Battery-Drain

Welcome to the board and hope this helps