Make sure you are using the correct connections on the mirror connector.This is now officially driving me nuts! Installed into auto dim circuit and all seemed to be working. ... then you start the car and it turns off. Turn car off it comes back on again. Suggestions? The 5v power unit had a live and accessories lead so ive just used the live feed and taped off the accessories feed.
Looking at the wiring diagram, the switched live is on pin 1 (Violet wire) and the ground is on pin 2 (Black & White wire). Pin 3 (White & Brown wire) is the LIN bus connection - you don't want to touch that at all.
I would also use the accessory (switched live) input on your adaptor instead of the permanent live input.