I had the radio replaced by a Kenwood DMX-957XR this past week. When I picked it up, the AC would only blow cold when set to 65 degrees and it would only blow on high when in auto mode. The outside temp was 75. If I changed the setting by as little as one degree, it switched to heat. The installers showed me that there is only three connectors on the back of the AC controls and they were all plugged in. Any idea of what they did wrong?

 

1) My first thought is they didn't plug in all the connectors well and one is loose. If they showed you all the connectors are plugged in, that is probably not your problem.

2) My second thought is they tied into a data line or cut a data line while doing the install.

3) Just for kicks, I would disconnect your car's battery for 10 minutes and see if that resets your AC computer

 

They did run the battery down and had to put it on a charger.

 

I would still disconnect your car battery for 10 minutes and re-hook it up

 

This indicates the crossed or shorted wires somewhere. I would unplug the new stereo to see the problem goes away.

 

did you disconnect the battery as Daryl suggested?

When in auto, set to 65 and blowing cold, can you reduce the fan speed when you push the fan control?

When you said t switched to heat, did you mean the vents switched to the floor or really hot air came out of the vents?

 

I did try disconnecting the battery. That did not work. When in auto, set to 65 and blowing cold, I can reduce the fan speed. When I change the temp setting to 66, it changes the vents to the floor and hot air comes out of the vents. I can change the vent choice using the mode button, but hot air comes out.

 

Do you guys think his car doesn't know what temperature it is in the cabin? It thinks it is 65 and when he goes to 66, it turns on the heater to reach that temp?

Anyone know where the inside temp sensor is?

 

You are amazing Daryl, it could be his problem, I cleaned mine once in the 2002 because it was nasty. Makes me wonder if they disconnected it or it could be dirty. See before and after pics, plus location below.
it’s on the lower dash in front of your right knee…the Third pic is from a ebay pic…not my car.
this was the 2002-2005 configuration.
The tube connects to the HVAC air box and the fan pulls cabin air over the sensor.

if the installers removed this panel, they might of disconnected the plug or when they removed the old radio, they disconnected this plug by mistake.
not saying this is the problem but something to check.



I used a sensor cleaner

 

I was thinking the same thing, that one of the temp sensors got disconnected during the stereo upgrade. When one can only get hot or cold air at the extreme settings, it indicates to me the HVAC system is in some kind of "limp mode."

 

Success!!! Thank you Daryl! They didn't notice the wire for the sensor when they put the panel back.

 

Good for you and good to know. I’ll save this for future.

 

Excellent, glad BGW's info got you back on the road to happiness and cool air