98 4X4 burban

iTrader: (1)

2000 camaro

Today I replaced the BCM in my car to correct a security issue I was having. I bought a steering column with a key and key fob and the matching BCM. The problem has been corrected but another problem was created.
The dome lights do not work. everything else works properly, I can turn the map lights on with the switch on the mirror. The radio turns off when the door is opened. the dash lights dim with the dimmer switch. The hatch release works.
Every thing works,
could this be a programming issue? if so can someone tell me how to fix it?

bill12690

iTrader: (4)

I could be way off but that sure sounds a lot like a BCM issue. Obviously it's recognizing when the door is open, and the lights DO work, but BCM is not telling them to turn on when it's supposed to. Do they light up/turn off then the car is locked/unlocked with the remote?

98 4X4 burban

iTrader: (1)

No they do not.

WhiteBird00

iTrader: (4)

Bill is correct - the BCM controls the courtesy lights including the theater dimming effect. The power feed on the dark blue/wire wire is working since your map lights work so check the return (ground) wire... it's the white wire in position D1 of the blue 32-pin connector at the BCM.

Sounds like you went to a lot of trouble to fix something that 30 minutes and about $2 worth of resistors could have solved.

wssix99

iTrader: (5)

Is this a new BCM from GM???

98 4X4 burban

iTrader: (1)

Thanks for the info, I'll check it when I get home. I tried to fix the problem several times with resistors and could not get the BCM to read them.

98 4X4 burban

iTrader: (1)

Ok here is an up date
the dome lights still do not work. I can use my power probe and give the white wire a ground and the lights will come on. i also checked the signal coming in from both doors as well as the manual switch. i thought it might have been a programming issue but that was not it either.
why does everything else work but not the dome lights?

WhiteBird00

iTrader: (4)

It certainly sounds like a BCM problem. The BCM provides power to the courtesy lights on the dark blue/white wire almost all the time so that the map lights will work on demand. The only time it turns off the power is when it "goes to sleep" about 15 minutes after you turn off the ignition as part of the battery saver circuit. The map lights have separate ground paths through the black wire at the mirror. The BCM controls the courtesy lights by varying the ground availability on the white wire. It provides full ground to turn them on and then gradually turns up the resistance to provide the theater dimming effect until there is no more ground and the courtesy lights are off.

Since you can get the lights to work when you add a solid ground to the white wire, it is apparent that the BCM is not providing that ground. It could be an electronic problem but more often than not it is a broken solder joint on the BCM board that can be fixed by re-soldering (if you can find it).