trunk light

[mike561]

I recently replaced my body control module on my 98 GP, and i noticed after the car has been sitting for a while (without opening any doors) but if i just open just my trunk first, the light wont come on, but when i go to open a car door then it will come on, then when i close all the doors and all the interior lights dim out, the light will then stay on in the trunk if i open and close it, i have to do that each time the car has been sitting for a while. i notice it started doin it after i got the new BCM and dont recall it ever doing it when i had the old one in. i DID take it to the dealer and they programmed the BCM and everything, everything works fine except the trunk light not comming on with the trunk lid unless i open a car door first.

[BNaylor]

Not again Mike561. You seem the have the weirdest electrical problems.

The BCM and programming sounds OK but you never know since it was replaced. Do the interior courtesy lights work OK? If so the same 12v is shared from the BCM module. However, here is the major difference. The rear/trunk compartment light has an electrical check valve called a diode in the circuit because a sensing switch is used whenever you open and close the trunk. It may be either shorted or open. It allows a positive voltage to be applied to the trunk light but prevents the ground from returning to the BCM module. One side of the trunk light sensing switch is always tied to ground. The diode is supposed to be located in the trunk area where the sensing switch is located. Good luck!

[mike561]

lol yea i know, these electrical issues are getting to be a real pain, but yeah all the interior courtesy lights work fine, i think i know what you mean about the positive charge and the ground, im guessing all this located under the carpet somewhere in the trunk or around by the rear speakers. if so what should i be looking for and doing? would anyone happen to have a pic or diagram of this also? if not its alright, i just need to know where the switch is in the trunk. thanks again for the help!!!!!

[BNaylor]

Originally Posted by mike561

lol yea i know, these electrical issues are getting to be a real pain, but yeah all the interior courtesy lights work fine, i think i know what you mean about the positive charge and the ground, im guessing all this located under the carpet somewhere in the trunk or around by the rear speakers. if so what should i be looking for and doing? would anyone happen to have a pic or diagram of this also? if not its alright, i just need to know where the switch is in the trunk. thanks again for the help!!!!!

All the wiring diagram shows is the diode is located at rear of vehicle in trunk area maybe under package tray. It is tied in between the output of the BCM and to one side of the trunk light. But there is a high probability it is under the wiring harness plastic covering or someplace like under the package tray or trunk lid itself. You'd figure they would put it at the location of the trunk light socket but I don't think that is the case. As for the sensing switch to turn the light on or off it is part of the trunk power release and latch assembly. That is the only info I have.