Hello,

I'm new to the forum and to the 94 Camaro v6 5-speed I purchased, but I'm not new to working on cars. I do have a stumper here and was wondering if someone could provide some help. I've been on shbox.com and looked here but don't see anything specific to my issue.

It started with the battery going dead so I replaced it with a new one. It also went dead (in three days sitting in the driveway). I charged the battery and found that it had a 12.4v draw off the negative cable using my multimeter in series. I removed the power wire cluster near the battery and the draw dropped to zero. I found that the power connector with two gray wires (one to the BCM or RAP and one to the headlight switch) was drawing 12v. I cut the wires and found it was the one going to the BCM. I then put a test light on it and found that it was providing a ground (test light alligator clip on the positive battery terminal and probe on the BCM/RAP wire would light up the probe). I rigged up a relay that powers up the BMC/RAP when the key is turned to the "Run" position and the car will run but don't want this to be a permanent solution. We drove it around a few times and the car ran/started/stopped fine.

I pulled the BCM and the ground is still present.
I looked for the RAP module in the "pocket" under that dash but it's not there (did 94 have a different location? is it in the BCM?)

We also found that the alternator wasn't charging and replaced it. Now, strangely, the car has a hard time starting and seems to be flooding during a cold start (I did check that fuel wasn't coming out of the vacuum line on the fuel vent line module). If you "catch" it by letting the key go while cranking it'll start and run fine. If you keep cranking it'll never start on it's own and smell like fuel. But that's another story...I'd like to resolve the grounding issue.

I was going to start disconnecting items under the dash that might be faulty. Like the ignition harness, the BCM (already tested but I'll do it again), the Express Down module, etc. We've already pulled every fuse in the car and it's still grounding so I'm at a loss.

Thanks for any help you can provide.
Kevin

 

Ok. So reading more online (conflicting info I might add) it seems that what I thought was the BCM is actually the DERM (airbag module).

So, if the RAP isn't in the pocket in the middle, could it be next to the Express Down module that's mounted to the left of the steering column?

 

Figured out the hard starting part. A vacuum line popped off on the rear of the intake. Hard to see but easy to hear when the car was running. We put it back on and it's starting much better now.

I may need to bring the car to a shop that specializes in electrical faults to figure out why the RAP wire is showing a ground.

 

The RAP is going to draw current for 10 to 15 minutes after the ignition is turned to OFF, unless one of the door is opened, in which case it should turn off immediately. By the way, you should be testing for current draw (Amps) not voltage. Current draw is what is killing the battery. In most cases (until a fuse blows ot the battery goes flat), voltage will tend remain constant, while current may or may not be present.

 

94 does not have a bcm.

 

I'm pretty sure I was measuring draw. I also tested it several hours after turning the car off (the next morning actually). So the RAP should have been powered down.

- Remove negative battery cable and put multimeter on volts (milliamps went out of range) and put one probe on the disconnected cable and the other probe on the negative battery terminal (in series) and the draw was 12+ volts. Disconnecting the RAP wire from the positive cluster caused the draw to drop to .03 (vs ~12.4).

Putting a test light on the positive terminal and touching the RAP (positive) wire caused the light to turn on - indicating a ground. I verified by touching the strut mount and the light lit up again. So something is grounded in the wire that goes from the positive cluster to the RAP wiring.

Thanks for your help. I'll follow up when (if) I track it down. I'm on vacation next week and will be troubleshooting it more.

 

Couple of updates:
- I found that if I unplugged the large connector under the drivers side dash (unbolted actually) then the ground went away when testing from the battery end - so this would indicate the ground was inside the car
- I found that if I pulled both the PCM BATT fuse AND the Courtesy fuse the ground went away - so this would indicate it was something along those circuits

If I missed a ground for the PCM (in the engine compartment) would that "feed back" a ground through the circuit? Any common issues you might think of that would cause this? The ground isn't bad enough to fry a fuse, just showing up on the test light and enough to kill the battery after a day or so.

 

Bad wire to the glove box light. No more ground issue.

 

good tracking, so where are the pictures?

 

Oh. I got a picture for you. Ground issues are NO FUN! I ended up taking the car to my Uncles shop and a VERY talented mechanic traced it down for me. Here's a picture to give you an idea. He pulled every module in the car to rule it out, including the dash cluster. Then pulled each wire off the fuse panel until the ground went away. Then traced the wire involved. The glove box wire was chaffed near the drivers floor AND the wire was pulled out at the glove box switch and was touching the ground wire. He cleaned it up and plugged it back in securely. Good grief.