Tailgate Light Switch - Which Wire??? (1 Viewer)

[96TrailSurfer]

I've set up extra lights in the tailgate and wanted to have them come when the tailgate opens. Stock rear dome light is ground switched - with the switch in the tailgate latch. When the tailgate is closed, dome lights have a ground.

Inside the tailgate is a 20 pin connector to the tailgate ECU, and 3 smaller connectors. The grey 10 pin connector goes to the latch switch - when I unplug this connector, the dome light goes off. The other connectors have no effect on the dome light.

- The wiring diagram says that the tailgate switch connects R-W from the courtesy light to W-B ground.
- The grey 10 pin connector has both R-W and W-B
- The grey connector definitely controls the dome lights.
- I took apart the tailgate switch and saw that it goes to a 2-pin connector with R-W and B-W wires.

BUT!!!!

Both R-W and W-B pins on the grey connector are always grounded, whether or not the door switch is open or closed. Tripping the door switch makes no difference.

And yet this connector controls the dome lights.

WHAT AM I MISSING???

 

[gnob]

The switch is on the ground side of the loop?
You need to pull a different power source and use the switch to ground only.
The voltage is "used" before it gets to the tailgate switch.
With non powered circuits the meter will sometimes show the power side to ground. Not always legit.

 

[96TrailSurfer]

The switch is on the ground side of the loop?
You need to pull a different power source and use the switch to ground only.
The voltage is "used" before it gets to the tailgate switch.
With non powered circuits the meter will sometimes show the power side to ground. Not always legit.

All this I understand. I’ve pulled power, and everything works. The only thing I can’t find is the wire that grounds with the latch switch

 

[gnob]

You basically want to be connected at the red wire at the actual tailgate switch. Its likely grounding inside the gate.