The switch in the door latch closes when the door is opened, supplying a ground for the wire that comes from the TIPM to the latch.
The TIPM senses the ground connection, and tells the cluster what to do with the interior lights.
That ground wire is black, or black with a white tracer, (depending on which side of the connector you are looking at), and can be found in the door's wire harness connector.
I see no indication in my service manual what the door latch wire carries for power. You will have to open the door and probe the wire with a volt meter to see what is there.
Even if you find it has 12v on it, you don't know how the system will tolerate having a lamp, LED, or a relay coil connected to it.
I believe what people usually do to add lights to the interior lighting circuit is tap into the dome light power feed wire.
2008 Unlimited Rubicon Automatic
Last edited by ronjenx; 01-27-2018 at 09:02 PM.