Mirror Turn Signal Wiring
 

Hello. On my 2010 ML350 (W164), the right mirror turn signal is not functioning. There is an indicator on the display screen telling me the right mirror turn signal is not functioning and the signal flashes twice as fast as normal.

I disassembled the mirror and find 4 wires going to a connector that feeds the LED mirror turn signal and the right side marker lamp. 3 of the 4 wires are broken and the 4th is damaged (the insulation is cracked in multiple places). I understand this is a common problem related to folding the mirrors when the vehicle is locked.

I can make the LED mirror turn signal flash if I connect the broken ground wire from the connector to either of 2 of the 3 broken wires coming from the vehicle. I can also make it flash if I connect a jumper wire from the broken mirror ground wire to the ground stud in the engine compartment. But neither method "cures" the dash warning message and fast signal cycle. I can't figure that part out.

Do more than a hot wire and ground wire connect to the mirror turn signal?

Anyone have a suggestion?

Thanks.