Anyone know where and what the switch looks like in the tailgate that makes the rear interior light come on? My rear interior light won’t come on.

I tested the door switches to the light and they are ok. I looked at the schematic and I see the door switch ground wire and tailgate ground come together at a terminal under the rear panel between the speakers. I removed the panel and disconnected the ground going to the tailgate switch and now the light comes on when I open the rear doors. So whatever is supposed to trigger the ground when the tailgate is opened isn’t working.

I just installed a new tailgate latch from MB thinking that would fix the issue but it didn’t.

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1985 300CD, CA
172 Anthrazitgrau/Palomino 154

1985 300TD, CA
040 Schwarz/Palomino 154/3rd row seat

1985 300TD, CA
473 Champagner/Palomino 154/Cargo cover