Issue with door switch - lights/running boards not responding

[craig72]

Hey gang,
I'm working on my 2016 Exped Platinum. The other day my bride told me that when she got out to the truck, she noticed that the running board was extended. When she go in, the lights came on as expected, but when she closed the door, the running board did not retract and the puddle and interior lights did not go out like they normally do.

I did some testing.
- FORScan shows B1175:01 Drivers Door Ajar Switch
- Replaced with 3F2Z-13713-AA. Problem remained. I checked the old switch and it worked as expected (normally closed, open when pushed)
- Interior lights do eventually go out after about 10 minutes if the car is off, which I'm assuming is the Battery Saver kicking in

The Haynes wiring diagram shows the Light Blue/Red wire from the door switch feeding the Interior Lighting System. However, when I go to that page, I can't really find it as an input. I'm assuming it goes to the GEM which acts as the control coils for the Interior Lamp Relay and Running Board Lamp Relay (which I'm assuming also somehow triggers the running boards themselves)

Any thoughts on where to check next? There's no real info on the GEM (number/location, ect).
Any help would be appreciated!
Craig

 

[craig72]

if anyone has a factory wiring diagram related to this area, that might help me track this down as well.
Thanks!

 

[Michael D Morris]

Check the voltage on your battery. When the battery gets weak, the vehicle shuts down non-critical accessories. I replaced my 5 year old battery and everything returned to normal.

 

[craig72]

Well, I finally figured out what the problem was here. It turns out the door switch attached to the latch had lost its signal wire. I had replaced the switch which is attached to the bottom of the latch, but that did not solve the problem. After much wire tracing, I determined that the 12v signal wire from the Body Control Module had snapped somewhere where the wire passes through the door. I confirmed this by grounding the signal wire at the BCM inside the passenger kick panel and watched the warning light on the dash go out. Using the shop manual I'd purchased, I determined that the wire harness came though the door, then went about halfway along the drivers door threshold and then crossed under the seats. There is a bundle of probably 70 wires, so it was a matter of digging out the green/violet wire. Once I found that, I cut the wire there and then also cut it on the door just past the C510 connector in the middle of the door. Running the new wire through the door boot was a real PITA. I used a piece of lubed Romex as a wire fish. I also had to move the parking brake assembly out of the way to get where the wire comes through the pillar. All appears to be working great now.
Apparently wires running through there are known to have issues over time due to the stress of open/closing the drivers door so much. Seems like poor bundling to me if its that tight.
So if you get any electrical gremlins in your doors, wiring could be the culprit where it goes from the door into the vehicle.