BCM Diagram/Wiring Info [Archive] - GrandAmGT.com Forum


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Dave C
01-14-2007, 07:03 PM
Trying to find a wiring diagram/schematics for the BCM. More specifically, I would like to know the power/dimming wires to the interior courtesy lamps (aka dome light). Thanks.

01-14-2007, 07:15 PM
What year?

Dave C
01-14-2007, 07:23 PM
sry. 2004 GAGT

01-14-2007, 07:26 PM
there is no "dimming wire" from the BCM, the wire supplies voltage to the dome light switch/dimmer switch module, then from there it goes to the dimmer switch which is a variable resistor that increases or decrease the voltage to the lights, dimming or brightening them. so that being said, do you need the conn from the BCM to the light module, or from the module to the switch, or from the switch to the light?

Dave C
01-14-2007, 07:51 PM
thanks for the help so far... I made a bad assumption. here's what I am trying to do:

the '04 GA didn't have floor lighting like the '99-'02(?) did. I would like add these lights and am trying to find the wires to connect to them.

what I have found out so far:
three wires come from the dome light/reading lamps (ground, power, dimming), running down the left c-pillar, then connect into a bundle running forward toward the front of the car. also I've found the interior lamps connection from the fuse panel to the bcm.

I was assuming that the BCM directly controlled the dome/reading lights. Can you give me more information about the dimmer switch module and where I can connect into the two wires to get power without running wires all the way back to the c-pillar?

Dave C
01-14-2007, 11:21 PM
anyway, I had enought screwing around... I just took apart the wiring harness under the back left c-pillar panel and added a couple of wires for power. thanks for checking in on this guys, and if you have any suggestions to get power a better way, let me know.

thanks again