Problem with dual zone climate control

[Davschmidt]

I have a 99 Regal. I recently changed my battery and the AC vents on the driver's side are blowing warmer air than the vents on the passenger side. I read in a post on this forum that the battery terminals may have been hooked up in the wrong order, thus messing up the computer that controls the AC vents. This happened before and hooking up the battery cables again solved the problem. Unfortunately this procedure has not fixed it this time. Any suggestions would be appreciated. Is it possible that the computer could be permanently damaged?

[BNaylor]

Is your climate control manual Dual ComforTemp or the automatic digital?

[Davschmidt]

I have a digital climate control panel on the dash. I replaced the control panel unit about 2 years ago.

[BNaylor]

That is a common problem on the digital system when the battery is disconnected. One step that helps is make sure the climate control is in the off position prior to ever diconnecting the battery. Otherwise one of the temperature actuators (drivers) in the dash hangs up.

You may have to repeat disconnecting the battery a few more times. Try disconnecting only the negative for a few hours, reconnect and then see what it does.

[Davschmidt]

I tried the battery disconnect again and it worked this time. Thanks for the help. You provide a very valuable service to dummies like me.

[MAYHEM01]

Originally Posted by bnaylor

That is a common problem on the digital system when the battery is disconnected. One step that helps is make sure the climate control is in the off position prior to ever diconnecting the battery. Otherwise one of the temperature actuators (drivers) in the dash hangs up.

You may have to repeat disconnecting the battery a few more times. Try disconnecting only the negative for a few hours, reconnect and then see what it does.

Ok gang, I have the same problem but with a tiny hitch. My Regal GS is/was doing the same thing. I had cool air on the passager side and warm air on the driver side. I have a Digital control. Well after I reconnected the neg post, the A/C clutch will not engage. I check all fuses and swaped relays to no avil. Any quick trobleshooting I can do to narrow down the problem?

Cheers

[BNaylor]

Originally Posted by MAYHEM01

Ok gang, I have the same problem but with a tiny hitch. My Regal GS is/was doing the same thing. I had cool air on the passager side and warm air on the driver side. I have a Digital control. Well after I reconnected the neg post, the A/C clutch will not engage. I check all fuses and swaped relays to no avil. Any quick trobleshooting I can do to narrow down the problem?

Cheers

Welcome to AF.

Although you checked the AC clutch fuse and relay are you getting 12 volts at the fuse socket and the low to the AC clutch relay? The relay is controlled by the PCM module based on the system charge. There is a high/low pressure switch. How is the charge at the low pressure port? Uneven cooling across the evaporator core can be caused by a low refrigerant charge if the battery disconnect does not work.

[MAYHEM01]

THanks for the warm welcome. I'll check that in the AM.

Cheers

[dmgatorcane]

I also have a problem with warm air on the drivers side and cold air on the passengers side, but mine is a Dual ComforTemp. Any suggestions?

[BNaylor]

Originally Posted by dmgatorcane

I also have a problem with warm air on the drivers side and cold air on the passengers side, but mine is a Dual ComforTemp. Any suggestions?

Welcome to AF.

If it is the dual climate manual then check the refrigerant charge at the low pressure port to see if low. Also, a good idea to check high side to compare the two readings. On a manual HVAC system a low charge is typically the reason for warm driver, cold passenger which is uneven cooling across the evaporator core.

[dmgatorcane]

Originally Posted by bnaylor

Welcome to AF.

If it is the dual climate manual then check the refrigerant charge at the low pressure port to see if low. Also, a good idea to check high side to compare the two readings. On a manual HVAC system a low charge is typically the reason for warm driver, cold passenger which is uneven cooling across the evaporator core.

Thanks for the info! After checking further, I realized it is the automatic digital control. I disconnected the battery about five times with no positive result and then disconnected the negative from the battery for about two and a half hours with the same result. Any suggestions on what I should try next? And thanks for your help to all of the posts that you have helped.

[BNaylor]

Originally Posted by dmgatorcane

Thanks for the info! After checking further, I realized it is the automatic digital control. I disconnected the battery about five times with no positive result and then disconnected the negative from the battery for about two and a half hours with the same result. Any suggestions on what I should try next? And thanks for your help to all of the posts that you have helped.

Have you verified the system is not low on refrigerant?

Other possibility for the digital climate control are the temperature control actuators. For dual there is one for driver's side and passenger. As the temperature is varied at the climate control these actuators move and control a temperature valve located in the lower part of the heater/evaporator assembly.

[-_-XtC-_-]

i had a similar problem prior to purchasing my regal gs... the vehicle wouldnt allow ac or dual climate to work, easily fixed by replacing the dual climate control unit. dealership did it for free for me, even though you would have to pay, this may be an option if you havent done it already.