Stereo & Electronics - Problem with HU and Power Windows

Hey,

My HU keeps cutting off and on by itself randomly while I drive. It was completely stock then I replaced it with an aftermarket HU... still stock speakers though. The aftermarket one does it also.

To make this odd, my power windows also will not work when the HU cuts off. My door locks work fine, just the power windows. Does anyone know if the HU and the power windows meet somewhere in the wiring? Anyone ever heard of this before?

Thanks.

I bought a haynes manual and I can't find anywhere in the wiring diagrams that the power windows and HU meet.

Anyone know?

I believe they are connected through the R.A.P. (Retained Accessory Power) circuit, and I'm pretty sure there's another thread on here about this problem. (pretty common) Not sure if there is a fix or not yet for it. I'm actually downloading wiring diagrams as we speak to try and figure something out.

Thanks for the info. I did some searching on the RAP and found that it's related to the BCM and that it usually needs to be replaced if its not something simple like a loose wire or dirty door open sensors.

Yup, replacing the BCM fixed the radio and window problem in my car.

Yup, replacing the BCM fixed the radio and window problem in my car.

Was this complicated to do by yourself? Did you have to let GM flash it? I heard the BCM controls your ignition security deal.

I have the factory service manual, and followed the procedure to install it. But, basically, you unplug the old one, plug in the new one, and turn on the car. The first use programs the BCM for your key pellet.

At least that was the procedure for my 97. Not sure if anything may have changed in later years.

-Rich

how much does a new bcm cost? my radio and windows do the same thing.

the headunit (radio fuse) and the power windows share the same circuit going into the fuse box.

Ryan

how much does a new bcm cost? my radio and windows do the same thing.

It was a little over $200 from my local Pontiac parts department.

Can you buy any BCM from any LS1 F-body? In other words, I have a 2000 SS with a M6. Can I buy a used one off of a 01 z28 with an A4 tranny?

Well, there were a few different BCMs (one with keyless entry, one with the alarm, etc).....but more importantly, if you are thinking about trying a used one, it has to match the resistor in your key. If you buy a new one, the first time you use it, it programs itself to match your key.

I just happened to stumble across this thread being that just in the last week my SS is experiencing the exact same problems. Now forgive me for asking but what does BCM stand for and where exactly is it located at? Before I did a search on this problem I was thinking it had something to do with my power antenna i just installed on the car being that everytime it happened the antenna went down but what I did not notice was that the whole radio and windows(as mentioned above) all would not work from time to time. Any more info is greatly appreciated!!

BCM is the Body Control Module. They started using them in 96 or 97? Before that, I hear the cars had a seperate RAP module (Retained Accessory Power....the system that gives the radio and power windows power after shutting off the ignition). In cars with a BCM, the RAP system is part of the BCM.

The BCM on my 97 TA was located behind the dash, on the passenger side, directly behind the glove box.

I can't emphasize enough to follow the diagnostic procedure in the factory service manual before replacing the BCM. I've heard people fixed the intermittent radio problem by wiggling connectors, or tightening grounds. I wasn't so lucky, after following the diagnostics, it pointed to the BCM (about $250 for a new one). If your problem is something other than the BCM, spending $250 for nothing would not make you happy.

-Rich

I ended up taking the advice of others on here and checked the wiring going to the BCM the other night. What I found about a minute upon troubleshooting was everytime I shook or grabed the wires going in to the BCM I was able to recreate my orginal problem with the HU going out along with my power windows. It did look like one of the pins was not secure and I proceeded to uplug the harness fix the pin and so far (cross my fingers) everything has been good since.

I ended up taking the advice of others on here and checked the wiring going to the BCM the other night. What I found about a minute upon troubleshooting was everytime I shook or grabed the wires going in to the BCM I was able to recreate my orginal problem with the HU going out along with my power windows. It did look like one of the pins was not secure and I proceeded to uplug the harness fix the pin and so far (cross my fingers) everything has been good since.

I'm having the same problems, I want to check the BCM wires as well. You have to pull the glove box out and the BCM will be behind that? There isnt a picture or step to get to it is there? Or is it pretty self explanatory? Thanks

I'm having the same problems, I want to check the BCM wires as well. You have to pull the glove box out and the BCM will be behind that? There isnt a picture or step to get to it is there? Or is it pretty self explanatory? Thanks

Well crap, I thought I had mine all fixed and then today right when I step in to my car after a long day of work I noticed the radio and windows are a no go:( But yeah its located right under the glove box on the right side. Funny thing was I left the underside of the dash off because I had a feeling this might come back and haunt me so I again found myself shaking the wire harness while driving the car just so I could get some tunes on the way home from work:) I have a strong feeling however something is still loose because on the drive home I noticed that everytime the HU loss power i had just went over a bump in the road however, I dont understand why in the hell this is all happening all of the sudden?? Its not like I was every underneath that area of the inside of the car dicking around with the wiring or anything so it leaves me puzzled :confused: Lemme know if you find out anything else on yours as I might end up having to take a closer look at it this weekened

Well crap, I thought I had mine all fixed and then today right when I step in to my car after a long day of work I noticed the radio and windows are a no go:( But yeah its located right under the glove box on the right side. Funny thing was I left the underside of the dash off because I had a feeling this might come back and haunt me so I again found myself shaking the wire harness while driving the car just so I could get some tunes on the way home from work:) I have a strong feeling however something is still loose because on the drive home I noticed that everytime the HU loss power i had just went over a bump in the road however, I dont understand why in the hell this is all happening all of the sudden?? Its not like I was every underneath that area of the inside of the car dicking around with the wiring or anything so it leaves me puzzled :confused: Lemme know if you find out anything else on yours as I might end up having to take a closer look at it this weekened

Yeah, ill be spending Saturday morning trying to fix this problem and a few other electrical related problems...we just need to all get together and bring some cold beer and brainstorm.. :chug: ..hopefully the solution is fixing a short or the BCM like stated above.

This same exact thing happened with my car. I thought I had it figured out, a loose connector. When I wiggled it, it would cut out. I tightened up the connector and it worked fine for a little bit, then went back to cutting out, like you state, usually when going over a bump. I was convinced it was wiring, and did more wiggling, and at one point, wiggled the BCM itself (after removing it from it's mount).....well, when I did that, something sparked inside it, and it smoked. After that, I had no power door locks, no interior lights, no radio, or power windows. At that point, I was pretty sure it was the BCM itself. ;)

Buying and installing a new BCM fixed it all, and everything has been working fine for a year now.

-Rich

This same exact thing happened with my car. I thought I had it figured out, a loose connector. When I wiggled it, it would cut out. I tightened up the connector and it worked fine for a little bit, then went back to cutting out, like you state, usually when going over a bump. I was convinced it was wiring, and did more wiggling, and at one point, wiggled the BCM itself (after removing it from it's mount).....well, when I did that, something sparked inside it, and it smoked. After that, I had no power door locks, no interior lights, no radio, or power windows. At that point, I was pretty sure it was the BCM itself. ;)

Buying and installing a new BCM fixed it all, and everything has been working fine for a year now.

-Rich

Whered you get your BCM by chance? Dealership? Price?

I got my BCM from my local Pontiac dealer part department. It was about $220 (a year ago) and I installed it.

-Rich

we just need to all get together and bring some cold beer and brainstorm.. :chug: ..hopefully the solution is fixing a short or the BCM like stated above.

Ya no kidding, not bad you didnt live down in TX otherwise I might do so then again if you end up fixing yours I might as well drive my ass down there and have you fix mine:) It looks now however I might wait till Mon. or Tues. to find out more, I have a brother whom is a very high certified mobile car audio installer and after talking to him he said I could bring in the car to the shop some late afternoon and well take a closer look at it then with shop equipment he has and start testing the wires so ill keep ya posted on how that goes. I should let you know since I also saw you asking but if indeed we do need new BCM's i just checked gmpartdirect and it looks as if they have them for $160 shipped which would probably be the best bet since Im sure the dealers are going to cost more.

Ya no kidding, not bad you didnt live down in TX otherwise I might do so then again if you end up fixing yours I might as well drive my ass down there and have you fix mine:) It looks now however I might wait till Mon. or Tues. to find out more, I have a brother whom is a very high certified mobile car audio installer and after talking to him he said I could bring in the car to the shop some late afternoon and well take a closer look at it then with shop equipment he has and start testing the wires so ill keep ya posted on how that goes. I should let you know since I also saw you asking but if indeed we do need new BCM's i just checked gmpartdirect and it looks as if they have them for $160 shipped which would probably be the best bet since Im sure the dealers are going to cost more.

Well $160 doesnt sound bad considering all the electrical problems Im having now. They all seem to tie into the BCM some how and since I checked the wires today coming to and from the BCM and the harnesses near the battery on the wheel well. I might just spend that and pray it solves it.

Yeah, I debated ordering my BCM from gmpartsdirect....but I really wanted it FAST....especially since so many BCM functions died on mine....so turned to the dealer. They got it for me the next day. It was so easy to install....I put it in my car during my lunch hour in the parking lot at work.

-Rich

just an update. I fixed mine by zip tying all the wires to where it pulls the BCM towards the rear of the car. If you moved the BCM towards the front of the car, it would die.

This drastically helped it. It still might flicker every blue moon but wow is it much better. I'm happy and saved 250 bucks. (that's how much it costs at my local dealer)