2006 Tahoe - Rear Wiper Not Working

[Rigg It]

5 wire connector - Pink and black is tailgate / lift gate, Orange is 12V hot, Grey is signal from wiper switch, Green is wiper wash, black is ground. Not getting ground on black wire have 12V on orange, pink and black and grey wires. Does ground come from Body control module?

 

[markvdb]

Run a ground wire from the wiper unit bolt to a grounding point in the rear door. It worked on mine.