Why do a 99 Olds Intrigue drivers side vent and driver side of the middle vent blow hot air when the air is on but the passenger side blows cold air even though both dials are set to cool?

Answer 1

I have heard a multitude of answers for this same problem which has plagued me now for almost two years. No solution has yet worked for me. Here is a laundry list from my memory as to what may be causing causing the problem.

1. Low freon. A mechanic once told me that the car will act like this when it needs a freon recharge. Such did not solve my problem, however.

2. Stuck door. There is supposedly a "door" (for want of a better term) inside the heating/cooling system that regulates temperature and/or cabin airflow. The door opens and closes according to the temperature and and dual climate settings selected. If this door gets stuck, it causes hot to blow out drivers side and cool on the passenger side. I am suspicious of this theory. Why would hot air correctly blow out of both sides? I had another mechanic tell me this one.

3. temperature sensor improperly reset. I read online that if the battery gets disconnected and reconnected improperly, it will cause a malfunction in the sensor responible for delivering the proper temp through the a/c system. The solutions posted were disconnect the battery and reconnect with negative terminal first; check all fuses that reference climate control, a/c , heater, etc in manual, remove for 15 seconds, reinsert or replace if necessary. This did nothing for me. However, I personally associate this intermittent problem with a battery reset. My wife's car has electrical problems (don't get me started) which necessitate frequent battery replacement. Everytime the battery has been disconnected, the problem starts again.

4. Computer malfunction. I also read that the problem may stem from the climate control interface itself (i.e. the thing with all of the temperature knobs and buttons). Replacing this is supposed to fix the problem. I have not tried this, and frankly, I refuse to do so.

The only current solution I have ever found is patience. The problem seems to simply disappear after a while (albeit a long while). My wife and I both have Intrigues (Gasp!). They both have the same problem(s). Nothing works for either. Good luck. If you have success post your results.

Not Much of an AnswerMy 99 Intrigue often does this, and I have tried replacing the temp control head, plus the door reset sequence (disconnect battery, open both front doors, reconnect battery, start engine with climate control on AC with temp dialed all the way down). Neither worked. In fact, the temp control head replacement was worse than what was in there, so I had them reinstall the original. I called GM tech support and got a sheepish answer that indicated to me that the hot/cold air at the same time thing is a design flaw. If you wait several minutes (if you can stand it) with the climate control set the way you think it should be, the "computer" comes around eventually. I have noticed that the AC on a very hot day with the car sitting in the sun will usually come up blowing cold air out both sides (thank goodness). Usually when you get the hot/cold it is a moderately warm day, which apparently "confuses" the thing for a while. I'll never buy a climate control car ever again.

Answer

The car seems to do this after the battery is disconnected, I tried everything that I saw on the Internet. The only thing that worked for me (immediately) was to remove the a/c heat control unit from in the car, directly below your cars radio/head unit. Take the cover off and remove the two screws, pull the unit out, unplug the wire harness and let it sit for 30 seconds. It will reset itself plug it back and the a/c will work again. Should take less than 5 minutes to do. MOST IMPORTANT

Or if unplugging the battery always remember to turn the a/c off before doing so. So that the a/c doors are shut when the system is reset. When replugging the battery they will start from the correct position and all will be fine.