Gentex Factory Mirror Wiring?

[Treetopflyer13]

I purchased a factory Gentex-120 with the dimming and compass features from salvage yard and want to install in my '95 Silverado. Problem is it has more than just power and ground, it has five wires total;Red, Black, Lt Green, Black w/White Stripe and Dk Green w/White Stripe. Can anyone tell me what is the purpose of these additional wires?

[LastOne]

I saw a note on some forum that the wiring is stuck in the headliner. All they did was plug it up. Good luck

[brbarcla]

The connections to a Gentex mirror (with comp and temp). The connector pin numbers are found on the wire incursion side of the mating connector.

GM / wire harness color / function
PIN 1 / PINK / POWER +12 volts
PIN 2 / BK / CHASSIS, GND
PIN 3 / LT GRN / BACKUP LIGHTS
PIN 4 /GY / TO AUTO DIM OUTSIDE MIRROR
PIN 5 / PINK / TO AUTO DIM OUTSIDE MIRROR
PIN 6 / DR GRN/WT / TEMP PROBE
PIN 7 / BK/WT / TEMP PROBE

Note: Pin 3 is to be connected to the backup lights to turn off the auto dim feature in reverse.

I have been told that "If you intend not to use this feature connect the LT GRN wire to chassis ground. If this pin is floating the auto dim will not work properly." I have not connected this yet and it seems to function propoerly except of turning off the auto dimm when the vehicle is put into reverse. Hope this helps.

[rboc]

Thanks for posting the information about the Compass Mirror Install.

I got a Gentex-120 from a '97 Cadillac STS. Mine came with a separate "black box" that was fastened to the windshield with double face tape (factory stuff). When I hook power and ground, I get the mirror to work, but the compass is stuck on N. Is the extra box part of the compass? Did your compass work?

The wiring to this box is almost like the mirror wiring. It has the same colors for power, ground and back-up. The other two wires are similar to the mirror, but not exact. (I don't have it in from of me right now.) I tried wiring the box the same as the mirror (power and ground and then tied the two remaining wires to the same leads on the mirror) but it didn't change anything.

My mirror has only five wires. I assume it doesn't have temp.

Thanks,

Charlie

[Powerwagontim]

Hi Charlie,
I did the same thing, only my mirror hasnt got the black box. I connected it up to the harness which was tucked into the headliner and also got just north and the temp didnt work. The compass needs to be calibrated, which is done by either driving slowly in circles a couple of times in a parking lot, or just drive around normally and it will figure itself out. The magnetic declination can also be adjusted, check your owners manual for instructions and a map showing your declination. As for the temp, you need to get the temp senser which mounts on the crossbar in front of the radiator ( about 15.00 at the dealer) and the wiring harness which goes from the temp senser to the electrical distribution box on the drivers side inner fender. Thats the hard piece. The dealer cant give a part # without a vin, and your vin wont call for that harness because it didnt come from the factory with it. I havent had any luck finding one in the local junk yards yet. The auto dim feature also works fine.
Hope this helps, Tim

[rboc]

Thanks for the reply Tim, but the black box wiring is what is stumping me. I think the box must have the compass electronics in it, but that's just a guess. Mine doesn't seem to have temp...but I could get the sensor off the same Casillac if it is there.

[Powerwagontim]

Hi,
My guess is that you are correct with the compass guts. I do know that the compass electronics are self contained with the mirror, so the box is probably that. I learned alot by doing ebay searches for gentex, silverado mirror, tahoe mirror etc. and read their descriptions. Some guys put alot of good info into their listings. I got mine cheap because the guy had picked a poor title and I think most people who were looking didnt happen on his listing.
Tim

[95ragtop]

The compass "guts" are in the plastic cover on the mount where the mirror attaches to the windshield. There is a wire from the back of the mirror to it. I you have a "black box" with 2-sided tape, it's probably a rain sensor.

[AaronIROCZ]

The black plastic box is the sensor for rain sense.

[95ragtop]

Originally Posted by brbarcla

The connections to a Gentex mirror (with comp and temp). The connector pin numbers are found on the wire incursion side of the mating connector.

GM / wire harness color / function
PIN 1 / PINK / POWER +12 volts
PIN 2 / BK / CHASSIS, GND
PIN 3 / LT GRN / BACKUP LIGHTS
PIN 4 /GY / TO AUTO DIM OUTSIDE MIRROR
PIN 5 / PINK / TO AUTO DIM OUTSIDE MIRROR
PIN 6 / DR GRN/WT / TEMP PROBE
PIN 7 / BK/WT / TEMP PROBE

Note: Pin 3 is to be connected to the backup lights to turn off the auto dim feature in reverse.

I have been told that "If you intend not to use this feature connect the LT GRN wire to chassis ground. If this pin is floating the auto dim will not work properly." I have not connected this yet and it seems to function propoerly except of turning off the auto dimm when the vehicle is put into reverse. Hope this helps.

******IMPORTANT *******
DO NOT CONNECT THE LT GRN WIRE TO GROUND. THIS WIRE IS 12V WHEN THE VEHICLE IS IN REVERSE. YOU WILL BLOW A FUSE.

[al blazer]

Hi guys I'm a rookie.I know this thread is old but I recently got a gentex-120 auto dim with compass with 7 pins and no wiring harness.First 3 pins are 1-12V+ 2-Neg 3-12V+ from reversing light to disable auto dim the next 4 pins are printed on the board as : 4- OEC+ 5- OEC- 6- OEC+ 7- OEC- .What is OEC? Your help would be greatly appretiated.

Al