Ron C
Full Access Member
On the existing rear view mirror connector you will find a blue wire (video -) and a white wire (video +). Those wires are located in pins 7 and 6 of the mirror connector respectively.
Purchase a 10' RCA cable and cut one end off. Strip the casing and you will find two wires inside that represent video + and video - but use an ohm meter to test continuity to ensure you know which one corresponds to the right signal. The outer shell of an RCA is negative while the center pin is going to be positive. Typically the video positive wire inside the RCA coax is an insulated wire while the negative is just bare.
Splice the positive wire into the white wire on the mirror and the negative wire of the RCA into the blue wire on the mirror. You can either cut them off from the mirror harness to move the signal or tap them in if you want to split the signal.
Route the RCA to the back of your navigation radio and connect into the RCA input for rear camera. You can tuck it between the headliner and glass, then route it behind the driver's a-pillar cover and down through the side of the dash so the cable is hidden.
Hope this helps.
I think that's the best way to do it too, if you already have a camera. Because you know there's a signal there.
Oh and here is the pinout for these "gentex" style mirrors.
Ron