Help! Lost my courtesy lights
Thread Starter
Racer
Joined: Oct 2007
Posts: 442
Likes: 15
From: FL
Help! Lost my courtesy lights
I replaced the heater core today and when done I find I lost my courtesy lights (well, partly). They were all there BEFORE I started and also still DURING the disassembly. I disconnected the battery at some point and when I re-connected it today, the lights were gone.
The crtsy fuse is good, I have power on the crtsy fuse and power on a thick ORN wire on the right side under the hush panel coming from the fuse box, but no lights in the doors, foot well, B-pillar, etc. and no hatch switch with doors open. BUT: I have engine bay lights and pwr door locks AND I can turn crtsy lights on with the light switch and then I have pwr hatch switch also. When pushing on the door lights they light up. The FSM suggests the delay timer as the culprit.
The TWO wires to the passenger footwell lamp (in the hush panel) BOTH have 12V! Shouldn´t the white one be sort of switched ground (by the door jam switch)?
I went back under the hush panel, looking for disconnected wires or damaged insulation, couldn´t find any. However, I did find one unconnected yellowish/tan 2-wire connector behind the ECM, wires seem to be brown/white and black. Plus I found a black plastic module with a mounting tab, could this be the courtesy light delay timer?
The crtsy fuse is good, I have power on the crtsy fuse and power on a thick ORN wire on the right side under the hush panel coming from the fuse box, but no lights in the doors, foot well, B-pillar, etc. and no hatch switch with doors open. BUT: I have engine bay lights and pwr door locks AND I can turn crtsy lights on with the light switch and then I have pwr hatch switch also. When pushing on the door lights they light up. The FSM suggests the delay timer as the culprit.
The TWO wires to the passenger footwell lamp (in the hush panel) BOTH have 12V! Shouldn´t the white one be sort of switched ground (by the door jam switch)?
I went back under the hush panel, looking for disconnected wires or damaged insulation, couldn´t find any. However, I did find one unconnected yellowish/tan 2-wire connector behind the ECM, wires seem to be brown/white and black. Plus I found a black plastic module with a mounting tab, could this be the courtesy light delay timer?
Drifting
Joined: Aug 2002
Posts: 1,775
Likes: 125
From: Birmingham AL
I’m thinking this would be the delay timer module. Had the same exact issue with a 2000 Cadillac Escalade 15 years ago. Always had to turn the lights on manually. Seem to remember researching and the delay module was the issue. Sold it before I repaired it due to Vortec Intake gaskets trashing the engine.
Thread Starter
Racer
Joined: Oct 2007
Posts: 442
Likes: 15
From: FL
In the second picture, the black plastic box with masking tape on it is the dome light timer. It is possible to jumper the terminal that has two wires in it (probably yellow wires) to the terminal that has the white wire in it, and the courtesy lights will come on when a door is open. The hatch buttons will work too. No delay, but costs nothing to jump the terminals and eliminate the box.
The orange wire at a courtesy light is hot at all times. When the white wire is grounded, the lights will be on, and the white wire will measure 0-V to ground. When the white wire is NOT grounded, the lights will be off, but the white wire will measure +12-V to a chassis ground, because the meter "sees" the 12V being passed through the courtesy light bulbs. Keep your meter on the white wire and ground / unground the white wire and you'll see the correlation between the lights being on or off, and the white wire testing 12 or 0 Volts.
The orange wire at a courtesy light is hot at all times. When the white wire is grounded, the lights will be on, and the white wire will measure 0-V to ground. When the white wire is NOT grounded, the lights will be off, but the white wire will measure +12-V to a chassis ground, because the meter "sees" the 12V being passed through the courtesy light bulbs. Keep your meter on the white wire and ground / unground the white wire and you'll see the correlation between the lights being on or off, and the white wire testing 12 or 0 Volts.
I jumpered the 2+1 white wires et voilá - lights! I also took out the module for repairs. Those pieces cost next to nothing but the vendors want $50 for a new module.
