Temp compass mirror conversion

Hi,
My 02 Silverado came through with the basic interior mirror. I bought one on ebay with a section of the wiring harness still attached. The truck has a harness for the mirror which was tucked up into the headliner. The temp senser is factory mounted below the radiator. Here is the problem. The compass works fine, it is self contained within the unit. The temp reads OC. The wiring harness which came with the mirror has 7 wires and the truck harness has 5 wires. Does anyone have a wiring diagram for these mirrors which will tell me what the other 2 wires are for, or do I need to find another mirror which takes a 5 wire harness?
Thanks in advance, Tim

I have an 01 and I did the same thing, when I plugged it in it read oc, so I went and checked to see if the sensor was there and it wasn't, I ended up buying a sensor and installed it in front of the radiator and ran it to the relay box under the dash to the lft of the steering column. There is a two way brown connector that runs directly to the temp reading of the mirror, hope this helps.

Do you remember where you connected the plug? I dont see any fuse labeled for the interior mirror in any of the boxes, or in the owners manual. What I am assuming is the senser is mounted below the radiator. Is this correct? I havent traced the wiring yet.
Thanks, Tim

The sensor should be right in front of the radiator, you should be able to see it in front of the radiator without even taking the grill off. The sensor you saw was probably undernieth the radiator, that is actually an airbag sensor. The dealer said that the factory temp harness is wired with the headlight harness from the main fuse box and that I would have to buy a sensor and connector and tap into the factory harness, I couldn't find the right wires in the harness so I ran the new sensor which I installed in front of the radiator and ran it through the fire wall to the brown connector that goes directly to the mirror. Dont worry about cutting and splicing the wires at the brown connector unless you have automatic temperature control.

i did this coversion on my 00 a short time ago. there should be no need to run a new harness for the sensor in the front of the truck. down at the base of the grill nearly behind the bumper cover there is a semi coiled harness tied up with a block off cap over a plug for the sensor. all that was needed was to buy the $12 temp sensor and the small plastic mounting for it.

note: 03 and newer truck have the airbag indicator light in the mirror, i believe the extra two wires are for that light.

The two wires on the mirror plug that are necessary for the temperature sensor are the brown wire closest to the driver side (when it is plugged into the mirror) and the green w/black stripe next to it. The three wires toward the passenger side should be common to all the mirrors. The other two wires are for the center mirror controlling the outside monochromatic mirrors, or that's what I was told anyway.

If the plug on your truck is missing the brown and green wires you can take each individual wire out of the extra plug that came with the mirror and insert them into the plug on the truck. This way you won't have to splice all the wires.

On the side of the extra plug you can see the silver tab that holds the wire into the connector. Push in on the wire, depress the silver tab with an ice pick or very small screwdriver, then pull the wire out. It may be necessary to push the tab back out before inserting them to the connector on your truck.

James