I'm having a problem similar to Rodger Davis, except my battery is draining down in just a few days.

I recently bought an 87 IROC That was in excellent mechanical condition, but had a few cut wires in the interior wire harness. I repaired the harness and and ran the car. All ops normal. So I come back a week later and the battery won't turn the engine over. It's a new battery installed after I bought the car. I've tried listening for pumps, fans or actuators running but I've found nothing.

With the car running I can read 14+ volts using a multimeter. So I start looking for a draw with power off. My meter won't read DC amps so I used a test light between the negative post and cable, postitive cable connected and key off. I disconnected the Alternator and removed all the fuses from the fuse box. I also disconnected the unswitched power lead to the radio and cigarette lighter. After each test I still get a light indicating something is pulling power.

So, does anyone know how many items are on an unswitched circuit in these cars? And, what would the normal drain be with all items connected and ignition switch off?

 

Ive got the same issues in my 87 TA...replaced all the wiring in the engine bay( battery, alt, etc), replaced my digital dash( it was defective anyways). I thought the issue was in the dash but was not. I am now on the hunt to. I wonder if it could be my rebuilt alt? I am at a loss right now to.I even changed out the fuel pump, sending unit since my gas gauge was not reading. That is now fixed lol

 

Hey did you all figure out what was wrong with your battery draining issue?

 

Yes I did. I was going to post this today in fact. Here's what I did. I removed all the fuses and disconnected the wire from the alternator. I used a test light between the negative battery poll and the negative cable to see if there was still a draw on the battery. Each time I got a light and went hunting for an unswitched load on the battery. I couldn't figure what could be pulling current with no lights or accessories running. Then it dawned on me that the light was coming on because the engine comuter was powering up when I closed the circuit using the test light. So next time I tried it I held it for a minute and sure enought the light came on, but then went out. So then I reconnected the radio that I suspected was causing the drain on the battery and tried again. This time the light stayed on. The radio's LED display was always on and was always brite even with the switch off. Since I've removed it I've let the car sit for a week and went back and stated it. It started with no problems. I'm going to let it go for another week or two, and if it starts with no indication that the battery is low, I think it's safe to say I found the problem. I'm also going to install a trickle charger for long term storage.

 

Good to hear you got it fixed. Mine is somewhere on the acc circuit i put the light tester on the neg bat terminal and touch the lead and started pulling fuses till i got the acc fuse to shut off the light. My rear hatch motor went out about a week after i got the car and its completely off the car now but still cant seem to find it.