2000 Firebird - Electrical - Grounding problem

[acaba]

I finally got my new BCM from the dealer and it only took 2 weeks. First they orderd a _P_CM (powertrain computer module) that took 4 days. Then they orderd a BCM (2 days + Sat + Sun) but it was USED and already had the security key code burned in so the car would not start. I finally got a new BCM (3 days + Sat + Sun).

Once I installed the new BCM everything works fine. It has been cool out, but not a single problem with the window/radio for almost 2 weeks now.

You can remove and open up the BCM really easily (at least on the '96 Camaro) for testing. I put an ohm-meter across the relay that controls the window/radio and found that by flexing the board I could make the resistance jump. My mistake was trying to artifically actuate the realy. I took an 18V battery pack and jumpered across the control side of the relay to see if it would energize and close the contacts correctly. Not sure if I reverse biased something or if my bad soldering job caused a short, but I really fried one of the ICs when I activated the realy after my fix.

Hope this helps you diagnose your problems.

Aaron

P.S.: Do you have a copy of the GM service manuals? I bought them for ~$160 and they have easily saved me that much in repair bills. I don't mean the crappy Haynes manuals, I mean the 4" thick GM manuals. They really help when tracing circuits, or even just trying to remove the dash board.

[Sevenpelicans]

HI,

I believe I am having the same windows radio problem. Actually I know I am having the problem. It happens all the time. However, I am assuming it is from the BCM like many of you have experienced. I purchased a BCM on ebay. The guys said it was new but, I have no idea if it is. I am curious if anyone has any information on how to go about installing the BCM? I understand there is some way of programming it to the car and remote lock key chain? Any info would be appreciated? Also, does anyone know if it can be reset or does it absolutely have to be brand new? Thanks for your time. This thread has really given me some idea's on how to fix my radio problem.

[Wattsyurz]

The thread was quite old, I wonder if there was a resolution. I had a similar problem with my '00 Vette, where the driver door had connections that needed tightening. If closing doors and bumps affected the symptom, I would have voted on a mechanical fix like my loose connector. When the connection would go out, several things went including the radio, TCS, windows, locks, even the fuel gauge! I found that closing the door firmly would bring it back, which led me to examine the connectors in the door. I haven't had my '00 T/A door panels off, but the connectors are probably of the same quality. The female portions of the pins were notably oversized on a few of the connections, and can be carefully nudged tighter. Let me know if you find something. Even though I haven't seen this problem yet it would be good to know.

[Sevenpelicans]

Alright. So, I replaced the BCM on my 2000 Camaro today. Its seemed to do the trick for the radio windows problem. I tried both of the BCM's a few times and for some reason even without any movement the old BCM would just lose power to the windows and radio. I looked at all the wiring and the connecdtors everything looks good. The new BCM hasn't done it since. So, I was pretty happy. THe only problem I ran into was that my BCM wasn't exactly new. I bought it on ebay and the guy who sold it had already installed it. When I put it in it worked, and the car started but, the security light would not go away. After following the manual instruction for programming the BCM I still couldn't get the security light to go off. I reprogrammed it to the keyless entry and that worked fine but, still the security light is on. The manual says that a BCM can only be programmed once and is programmed to the car the first time its installed and the ignition is turned on. Does anyone know how I could just shut the security light off? I don't know if its affecting the alarm but its definetly not affecting anything else.

[1sadboy]

I own a 1996 firebird with exact symptoms. Radio and window would intermittently go inoperative. In high heat days, it seemed the problem was more severe. I repaired my vehicle today!!! Yee ha. It is definetly the Body Control Module, which is located behind the glove box, accessed by removing the panel directly beneath. There are 3 (looks like 2, but there are 3) multi-pin connectors in the BCM. Easy to spot from there. Disconnect the connectors and slide the BCM down and out. Takes a little effort. There was a cold solder joint on one of the 4 relays in this box. Simply touch a pencil tiped soldering iron to each of the solder joints. It's worth you while trying to fix your BCM, as your remotes are programmed via this module, and it's also matched to your ignition key resistor (for anti-theft measures). Replacing with a used BCM will take some working around these issues, and buying new will cost you - Good luck.

[oldgray]

My '97 has the same problems too. I took out the BCM and saw a solder connection that looked iffy so I fixed it. The radio and windows are still working off and on but my wife found that they work if she applies pressure to the dash on the right side of the radio. I'm assuming that the dash applies pressure to the radio which applies pressure to a wire harness back there. I removed the radio and looked in there and everyone looks and feels okay. Any idaes?

[Ralph123]

I have to correct my last post. The spark plug wire DIDN'T fix the windows-radio loss of power problem. The problem is definitely in the BCM (body control module). I unplugged the 3 connections to the BCM and plunged them back in and it fixed the problem. My solder joints looked OK. You have to use a screw driver and push in on the sides of the 2 smaller connections to disconnect them. If you want to pull the BCM all the way out here's a tip. with your fingers pull the bottom of the plasctic housing hard toward you while you push the the BCM back out of the housing then you will be able to pull it down and out. I know this thread is old but this is one of the first links that comes up if you Google this problem. Hopefully this will be the last word on this problem. Here's another great link with pictures and instructions about this problem. thanks
http://www.ls1tech.com/forums/genera...blems-fix.html

[Ralph123]

"Holy thread revival Batman."
After a year of dealing with this problem of intermittent loss of power to my power windows, radio and convertible top (all happening at the same time) I was able to fix it by putting a drop of solder on some circuit joints in the BCM (body control module.)
At first I thought it was it was just loose connection at the wire harnesses but that wasn't it.
The hardest part is getting the BCM out. It's located behind the glove box. You can see the BCM if open your glove box and pull the sides of the glove box in and the glove box will drop all the way to the floor but you can't remove it through the glove box opening. You have to remove the bottom panel and side panel the push the the BCM back while you pull the plastic housing toward you to free it from the housing so you can pull it down and out.
If you don't feel comfortable soldering you could try using a conductive epoxy. Dupont makes some for repairing rear window defoggers.
Below is a photo of the BCM circuit board with the 5 joints in question. They are the large joints shaped in a T. The hairline cracks in these joints are very small. I had to use a magnifying glass to see it but they are there.
Click photo below to enlarge
and here is another link that deals with the same problem.>>> http://www.ls1tech.com/forums/genera...blems-fix.html

[oldgray]

Ralph, thanks for the link and the picture, I tried this once before but I wasn't sure which solder joints I should check or the need for a magnifying glass. I guess I'll give it another shot this weekend. Otherwise, I'm going to disconnect the stereo from the BCM controlled power supply and tie it in with the cigarette lighter or something else that's handy. I can live with the windows working off and on. We live on the coast and everytime we go over a bridge, the stereo freaks out.

[pharaohxander]

This was very helpful. I have been having the same trouble with the windows/radio turning off while driving. I re-soldered the relay connection per the photo above and it fixed the problem. took me maybe 30 min (most of which was spent removing the module from the car and making a soldering iron since i dont have one lol.)

PS wrapping piece of 10 gauge copper grounding wire around the nozzle of a propane torch makes a great soldering iron. just bend the end of the wire 90 degrees across the flame so that you dont torch the circuit (flame up, wire tip down)