Well, the switch talks to the body control module (BCM), mounted under the rear seat.
The rear wiper motor (with has an internal processor) talks to the liftgate Module (LGM), you guessed it, inside the liftgate.
The BCM and the LGM communicate over a serial data bus.
I think the problem is in the rear. At the wiper motor assembly, the LGM, or the wiring going into the liftgate. Might be a broken wire (in the bundle where the bundle hinges at open), or perhaps a bad ground, in the gate, or in the bundle going into the gate. The grounds, by the way, are black wires.
The rear wiper motor (with has an internal processor) talks to the liftgate Module (LGM), you guessed it, inside the liftgate.
The BCM and the LGM communicate over a serial data bus.
I think the problem is in the rear. At the wiper motor assembly, the LGM, or the wiring going into the liftgate. Might be a broken wire (in the bundle where the bundle hinges at open), or perhaps a bad ground, in the gate, or in the bundle going into the gate. The grounds, by the way, are black wires.
