Wierd Electrical problem, Help!

**mcamp001** · 11-13-2009, 04:47 PM

I have a strange problem that I cannot seem to figure out. Let me know if anyone has some ideas for this one. Car's electrical has died, what I mean is; when turning the key on, all system lights and chimes come on ok, but when going to engage the starter, boom, everything goes dead, flat dead, no lights, no nothing. After this happens, when I open the drivers door, I get a clicking noise, sounds to be coming fro the front passenger side, possibly from the computer?

If I disconnect the battery and re-connect it, I get back to the same spot, at first all is normal, then when turning the key all the way to engage the starter, dead.

I have:
checked all fuses
pulled the starter and had it tested, passed
looked for any burnt or loose wires

I will tomorrow:
try to hook up Autotap to check for codes, as long as I can get power when turning the key on.

Also, when this happened I had to get flatbedded home, and I noticed when the car was on the truck and we hit a decent bump in the road, the alarm would beep a few times. It did this several times on the way home.

Possible theories I have:
Still a loose or burnt wire somewhere
VATS? - I can disable this via tuning SW if I can get power up
Computer problem?

Car has a rebuilt motor and several things done to it, but not in the last three years,and the time since then it has run flawlessly, so I rule out anything with the motor install or such. This is a 2001 SS BTW.

Any help is appreciated!

**bigrondownhiller** · 11-15-2009, 08:21 AM

Check the battery and the connections. Sounds more like a loose or bad battery connection. Dont forget to pull off both cables and check for corrosion.

**KahanaReef** · 11-15-2009, 08:26 AM

I had the same thing happen when my battery went dead. I hooked it up to the charger, tried starting it up and had that clicking noise too.

After the battery was fully charged, all was good.

**Smittro** · 11-15-2009, 08:39 AM

Possibly the BCM or (body control module) very common in or cars for the unit to fail..
It's located up under the passenger side of the dashboard, remove the under dash plastic plate. It is located in the void closest to the front of the dash, very easy to see and replace.. It has been noted, poor soldering from the factory on sertain conponets on the board..

**Smittro** · 11-15-2009, 08:46 AM

Recently posted BCM for sale..

http://www.ls1.com/forums/showthread...&highlight=bcm

**Smittro** · 11-15-2009, 09:10 AM

This is the removel proceedure posted by another member some time ago. I've done it myself a couple of times now to correct various electrical prods associated with the BCM.
I tried soldering it myself, but it easier to just replace it and be done with it..

Under the glove compartment, there is a panel that has 2 plastic pins that you just pull pull out with a pair of pliers - just be careful as you'll need them to put the panel back on. There is also a clip near the firewall (at the back of the panel) but I found that I had enough room after removing the pins and letting the panel just hang.

Once the pins are removed, the BCM is on the side closest to the passenger door and you should see several connectors plugging into the bottom of it. The service manual suggested pulling the BCM out before removing the connectors, and as I later found out, the connectors have clips on both sides to keep the connectors from falling off. Definitely easier to pull off afterwards since you can't get to the backside of the connectors.

(At this point, I decided to turn the radio on and manipulate the connectors on the BCM, thereby flexing the BCM circuit board a little and noticed that the radio went in and out. That confirmed I was on the right track.)

The BCM is clipped into a plastic bracket. You will have to unclip the BCM and push it forward (towards the front of the car) then slide it down and out. The "clips" are just wrapped around the BCM and snap over it - they are part of the bracket and wrap around the BCM. So, what I did is cram your hand up and feel the clips (one on either side of BCM), and just pop them off while trying to push the BCM forward so they don't re-clip back into the bracket. You won't have a lot of room, but it's possible. Then when it's free of the bracket, try and pull it down and out - there are no connectors on the top of the BCM, just the bottom.

Once the BCM is out, use a small screwdriver and remove the clips from the 3 connectors. There should be 2 - 6 pin connectors towards the passenger side of the BCM and a larger connector on the drivers side of the BCM. The clips are on both sides of each connector. Once those are removed, you can remove the connectors and then the BCM is free. The BCM is just encased in a plastic box that is snapped shut. You can open the box and remove the board to inspect it.

On my board, I found that the relay closest to the passenger side had the bad solder joint (via magnifying glass). So, if you are looking at the bottom of the board with the connectors facing up (this should place the 2 - 6 pin connectors at top right), the bottom solder joint of the relay closest to the 2 - 6pin connectors, was my problem. The solder joints for that relay, I believe, were also the largest on the board. I touched both up to be safe and put back in the plastic covering.

Putting the BCM back in was a lot easier than taking out, just reverse the process.... connectors, connector clips, then slide back up and snap in bracket. Lift the panel back up and replace the plastic pins.

**mcamp001** · 11-15-2009, 11:59 AM

Thanks for the replies. I put the starter back in and wrapped some more heat shield around the harnesses near the headers and low and behold, it fired right up, so I really don't know what the issue is/was. I guess it could be the battery, although it tests ok, It's a red Optima, so they should last virtually forever. It the problem re-appears, I will take a look into the BCM. Thanks again!