sgp99

Last night I started my 99 coupe and found that the AC was blowing cold air out the center and driver's side vents and hot air out the passenger vents. I had the AC on auto set at 68 and the outside temp read 79. The passenger control was set in the middle of the temp gage. There are no codes in the DIC for the HVAC.

I checked for some past threads on this subject and tried some of the suggested fixes. I disconnected the battery for 10 minutes in hope that the system would reset...this did not work. I tried to adjust the temp settings and nothing changed. I even let the car sit overnight and started it up this a.m. The problem is still there.

Anyone had this problem that found a way to fix it? Any suggestions before I take it to the dealer?

Callsign_Vega

Sounds like one of the plenum chamber doors might be stuck.

sgp99

Is this something I can fix and if yes, how or do I have to take it to a Chevy dealer?

vstella

I had the same problem..take it to the dealer for the fix :yesnod: The sensor and the vent actuator are shot..you will need new parts..easy fix!! :D

z0sense

What sensor?

I just started having this problem. Except my passenger side is cold and my driver's side is hot.

It started yesterday also:(

Help...................

0vetteshop

There are temperature door actuators for the left and right side...Faulty actuators are common :yesnod:

spdnman

This worked for me. Pull 3 A/C fuses underhood and under passenger side kick panel (Underhood & Floorboard), Start Ignition & Actuator doors should reset. The internal air flow doors for the Left and Right vents of the Dual Zone unit are controlled by independent actuators. It is possible that somehow the actuator on one side got "confused". If you pull the fuse for the A/C unit and replug in, the A/C system will go through an initialization routine and move all internal actuator doors to their extreme Open and Closed positions in order to calibrate the limits. Once you put the fuses back in and turn the key to Start, let the system go through this process (you should hear the actuators doing their thing). Once that is complete, if you still have problems then likely the actuator is starting to go, but I would bet it was just a memory glitch.

college_guy

DON'T TAKE IT TO THE DEVIL ...err dealer :reddevil . If you don't feel like hunting down the fuses just disconnect the battery for a minute. Did this with mine. Now they both blow the same temberature :steering: Hope this helped

z0sense

My question is this.

If my "door" was messed up. How does anything come through it at all?

I mean, if it is messed up, wouldn't it just not have anything coming out? If it were open it would blow cold air right? How is it that hot air is coming out (at full speed)?

sgp99

spdnman,

I tried your suggestion of removing the 3 fuses. When the system reset the result was that the blowing hot air on the passenger side stopped, but there is still no cool air coming out the passenger side. I assume that there is still something stuck or not working in the system.

0vetteshop

It is a hot/cold door,not an on/off door ;)