auto dimming mirror installation...

[laneo2494]

went to the junkyard today and got an auto dimming mirror off of an early 90s caddy (deville/el dorado, dont remember) and ran into a problem...

...the wire coming from the mirror has the red and black (power and ground) wire, and i put that into the fusebox. then theres a green wire that i know nothing about. anyone know about the green one? what it is? where it goes?

[83tc]

light sensor, usually found on the dash?, i know the one that fits my towncar had a light sensor in the dash, cant find one though, find a newer chevy/pontiac/buick/oldsmobile and look on the dash area for something looking like a small alarm light, only kindof smoke/black looking, i know on all the newer(2000 and up) chevy /gmc trucks its right on the dah you cant miss it, and in 95 and up gmc/chevy s10 blazers its actually recessed in one of the dash speaker grilles, find it and pull it, shoukld be 2 wires, a ground and the sensor wire, mabye 3 wires(power as well)but most are simply a 2 wire, either that or go back and look in the caddy you ripped it from

i just tinted my windows, cheapest dim mirror ever, once its dark outside you cant see out or in, lol....

[gadget73]

Might be the reverse switch. I know the Ford ones have a hot, ground, and a lead to the reverse light circuit to flip the mirror up so you can see while backing up. Not familier with Caddy mirror wiring.

[laneo2494]

thanks for the input...

....turns out the green wire wasnt needed after all. i just connected the power and ground and the mirror seems to be working fine. $30 at the junkyard is a lot better than $80 online