Where O Where did my sensor go?

[wma4553]

I am stumped. Have a 99 tahoe with compass, temp mirror and the temp does not work properly. It is 100 degrees here but my mirror is warning me about icy conditions. I assumed the sensor was bad so I looked behind the grill for the sensor so I could make sure I would get the correct replacement, but could not find the sensor. I even removed the grill to make sure I was not overlooking it but no luck, I didn't even see a wire for a sensor to connect to. All the info I have found says it should be attached to the radiator center support. The only thing attached to mine is the horn. Any one have an idea where to look for this elusive sensor. Thanks in advance for your help.

 

[SunlitComet]

sound like it got cut out. it should be right where you looked. wires should be brown and lt green/black wires.

 

[wma4553]

Thanks, You may be right, but would I get any reading at all if the sensor was cut out? It usually shows a ridicules reading like -30 and then it will switch to ICE. I thought maybe the PO had replaced the sensor and relocated it for some reason but I can't find it anywhere, I have looked all over the front of the truck and can't even find any wires so if it was cut out they must have cut it somewhere near the firewall so I will look again in that area.

 

[SunlitComet]

manual says nothing about "ice" in the display but a cut sensor would display oc for open circuit or sc for short. oc will happens when circuit is open or perceived temp is below -40°. with that it stands to reason they may be cut and touching each other in a high-resistance sort of way so to speak.go thru the harness that runs along the bottom of radiator support. that is where they originally were.

 

[Yukon420SEL]

im going to say the wires are lose or brittle that go into the actual mirror, mine was doing the "ice" thing as well as telling me opposite temps all which turned out to be caused by a bad connection comming into the mirror itself

 

[wma4553]

Thanks guys, I will check the mirror connection and the harness tomorrow.

 

[turk]

Good thread... I had the same problem last year, but somehow corrected itself. Good to know how to fix the problem.

 

[wma4553]

You guys were right, I found the cut wires hidden inside the harness cover. I ordered a new sensor and now I have to find a 2 pin connector, maybe at a junk yard. Thanks again for your help.

 

[chevyboy831]

your local napa should have a harness "book" that looks more like a calendar with a lot of connectors for gm if you want to get a new one instead of a used one. just gotta make sure of what it looks like first. they may have it.

 

[wma4553]

Thanks. good info, I will check the local NAPA store.