1999 GP - Heater External Temperature Reading

[Double B]

My heater external temperature reading on a 91 degree day will read between -39 below and maxes out at 50 above. Most of the time it is -39 degrees and hot air blows out the heater when it is turned off. The problem is that with a -39 degree external temperature reading, the unit will not let me turn on the air conditioning. I just replaced the intake air temperature sensor, but do not know if there is something else I can do, i.e. reset the heater some way. I don't know if this is possible, but if you hold the driver and passenger knobs in at the same time for 5 seconds, then a -00 reading comes across the display. So I imagine that this is possible, I just do not know what to do once I get to that display. So, 2 questions out of this...

1. Any clue on how to fix the -39 degree external temperature reading?
2. If possible to reset the heater, how do I do this?

Thanks.

[Ripn12s]

Your external air temp sensor is shorted out.

Simple fix.

Open hood while standing infront of car look infront of the radiator on the left side. That is where the sensor is. Replace sensor and it should take 2 or 3 drive cycles for the readings to come back to normal.

Sensor cost bout $12 from dealer.

Good luck

Tim

[Double B]

Thanks. I located the part, removed it and found that one of the pins had actually broken off into the clip and has rusted into place. I will have to visit the dealer this coming week and see if they have a replacement clip that I can splice into the existing wiring harness. The part was easy to find and easy to remove. Thanks for the tip and I will follow up with the results.

[Double B]

I got the parts from my local friendly dealer. $8.14 for the Ambient Air Temperature Sensor and $23.66 for the connector. $33.95 tax and title. Had to cut off the old connector and splice together the new connector to the wire coming from the harness. Made sure that I had the Yellow and Green wires matching the original position on the old connector and wala... a 142 degree difference. From -39 degrees to 93 degrees all on one day. Thanks again Tim. I do appreciate the help.

[bradvdovjak]

Tim,

I am having the same problem. I just picked up the part from the dealership, but I can't find it on my car. Could you please be more specific about its location. Unfortunately I do not do much auto repair, so I could use the help.

Thanks,
Brad

If anyone else can give me help, I would appreciate it.

Originally Posted by Ripn12s

Your external air temp sensor is shorted out.

Simple fix.

Open hood while standing infront of car look infront of the radiator on the left side. That is where the sensor is. Replace sensor and it should take 2 or 3 drive cycles for the readings to come back to normal.

Sensor cost bout $12 from dealer.

Good luck

Tim

[Double B]

Brad,

Let me see if I can help... stand in front of the car between the license plate and the passenger headlight with the hood open. Look down and work your eyes from the front of the car to the engine. You will see the metal that the hood latch is mounted to, a piece of plastic then the metal that the engine is mounted to. Under the plastic piece between these two metal sections is where this is located and it is located towards the bottom of the car. You will have to remove the plastic piece in order to see it OR get under the passenger side of the car and look up. There are a couple of bolts to remove, but it is not difficult. Unclip the old part and clip in the new part. All done. Hope this helps.

[bradvdovjak]

You are the man! Thanks for the help and I will try it tomorrow.

Brad

[bradvdovjak]

Tim,

Thanks for the help. I was done in about 5 minutes. The hardest thing was finding the part on the car. I was half expecting a sign that said, "Brad, look here", but I guess nothing is that easy.