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GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29534
Experience:  GM Grand Master Technician 2007. 14 years experience.
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1999 Chevy Suburban: lamps..doors open..lamp control module..assy

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1999 Chevy Suburban dome and courtesy lamps do not come on with doors open. They do work with manual switch. A mechanic has replaced the lamp control module and the dome/overide switch assy. I believe the door jamb switches are ok.
Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.

The module will have those specific wires in it. The colors are important and Must match.
Customer: replied 5 years ago.

is the small gray box with the circuit board inside a different component. The circuit board looks like the lamp control modules I find online. I cannot find a box with the 5 colors you're mentioning. Thanks for the patience.

Ok, test each for power and see what there is, I will go back and see about the different colors.
Customer: replied 5 years ago.
I get no power to any of the terminals to which the lamp module plugs into
That's not the lamp module then
Customer: replied 5 years ago.
when I google 99 suburban, lamp control module, the little circuit board inside my gray box is what shows up. Sorry if I'm missing something, thanks for your patience
Do any get ground with the door open?
Customer: replied 5 years ago.

yes, the black, green, one of two brown wires, the yellow, and a pink all make continuity to ground, they also act as ground to a 12v power source at the lamp switch. There are two light blue wires and one brown which do not get ground

Which gets ground with the door open?
Customer: replied 5 years ago.
The black, the green w black stripe, one of two tan w white stripe, yellow, pink all get ground
Which one with which door?
NO white wire at all?
Customer: replied 5 years ago.

all doors open, or all doors shut, same wires get ground

None of this is making sense. CAn you verify the locaiton in the picutre as the highlighted one?
Customer: replied 5 years ago.

do I need to remove any heater ducts under the dash or is there something I am missing here? I am going to plug my little circuit back in and continue looking for the original 5 wires. Thanks for sticking with me

I will help as long as needed.
YOu may need to take the trim of around the lower left dash, but no to the heater duct.
Customer: replied 5 years ago.
I found the remote door lock box on the diagram, and right close by is a small relay box with two orange, one black, and one pink wire, no gray and no white
I am not sure what to say. Even with the remote door lock box, it should have the gray and white wire in there.
Customer: replied 5 years ago.
ok, I may have misunderstood, there is gray and white wires in the remote door lock box, do I use those?
Yes, ground the white, what happens?
Does the gray get ground with the doors, any of them open?
Customer: replied 5 years ago.
ok, I've got the drivers door open, when I jumper gray to white the dome lights come on. When I close the door the lights go off. It's finally getting exciting.
Ok, that confirms the remote control door lock module is bad.
You can jump those if you want or you can install a relay. Which do you choose?
Customer: replied 5 years ago.
when you say relay, you mean the remote control module right? Let's do that.
No, simple relay that you get from a part store so you don't overload the door jamb switches. Can you get a simple relay and I can tell you how to install.
Customer: replied 5 years ago.
Yes, I'll get it in the morning. Instead of replacing the module, we're going jumper with a two pole relay?
Correct. Wire it this way.

Get power from an orange wire nearby and put that pin 85. Connect the gray wire to the pin 86. Then get a ground wire that you run from the bracket to pin 30 and the white to 87. This way you are using the gray as a signal to turn the lights on and at 1/4 amp, there is not danger of overloading it.
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