Air Conditioning (but only half)

I have a friend with a 99 Century with dual climate control (selector switch under the radio). Of recent, the driver side no longer blows cool air. Does anybody know or have a trouble shooting guide that would lead me in the right direction to get started?

I have a friend with a 99 Century with dual climate control (selector switch under the radio). Of recent, the driver side no longer blows cool air. Does anybody know or have a trouble shooting guide that would lead me in the right direction to get started?

Your best bet is a Helm GM service manual. The Chiltons and Haynes are worthless on this type of problem.

Sounds like a possible HVAC head unit, a vaccum line, or vacuum actuator which controls the vent registers.

Are you getting any airflow on the driver's side?

Thanks! yup, got airflow, it's just hot air...

Would that make it the hvac head? Something tells me this is going to be a bigger pain in the butt than I'd like it to be!

Thanks! yup, got airflow, it's just hot air...

Would that make it the hvac head? Something tells me this is going to be a bigger pain in the butt than I'd like it to be!


The dual climate control system uses 2 temperature valve actuators. One for the driver's side and one for the passenger side. Because the passenger side is OK you can rule out other causes such as the in-vehicle temperature sensor, outside air temp. sensor, solar sensor and compressor/evaporative system.

Here is the basic operation: The actuators turn and move temperature valves in the A/C heater control module to obtain correct blend of heated air from the heater and cooled air from the A/C evaporator.

Therefore, there are two possibilities left. The left temperature valve actuator or the HVAC head unit itself with the controls and control module. Good luck!

Perfect, thanks for the clear up on that! I'll tackle it this weekend for them and hope it is which ever part i get off first! :D (that is, after I make sure I can afford the parts)

I have the same thing happening on a 99 century -- except i don't have dual climate controls. Air temp out of right center vent is down to 59 degrees. Left center vent air temp is around 75 - 80 degrees. It seems to get cooler as the car is driven longer, but the two vents remain unequal in temp -- always at least a 10 degree difference.

Let me know if anyone has a suggestion on this.

I have had the same thing going on with mine also,, but its not a dual control..what i'm getting is a vent mixture of very humid N.C. air on the drivers side when going down the road..when stopped it realy gets cold again,, most of the time I have to have it in Max control to get cool air on driver side..Hey in my owners manuel it says that there is a vent filter some where in the ac/heater sys. But dont tell ya where??? Does anybody know where this so called filter is?????? Thanks

I have had the same thing going on with mine also,, but its not a dual control..what i'm getting is a vent mixture of very humid N.C. air on the drivers side when going down the road..when stopped it realy gets cold again,, most of the time I have to have it in Max control to get cool air on driver side..Hey in my owners manuel it says that there is a vent filter some where in the ac/heater sys. But dont tell ya where??? Does anybody know where this so called filter is?????? Thanks


The filter is called the cabin air filter. Its located on the passenger side of the vehicle at the intake cowling right below the windshield wipers.

The plastic trim panel has fasteners that you undo and then lift the trim off. Underneath you'll see the filter. Filter has a pull tab. Pull up and out towards the direction of the motor. A Fram replacement runs about $20.

I have the same thing happening on a 99 century -- except i don't have dual climate controls. Air temp out of right center vent is down to 59 degrees. Left center vent air temp is around 75 - 80 degrees. It seems to get cooler as the car is driven longer, but the two vents remain unequal in temp -- always at least a 10 degree difference.

Let me know if anyone has a suggestion on this.


Check your Freon level. It should be colder than 59 deg anywhere you check it. You could also have a vacuum controlled actuator going bad. :eek7:

I have a 2000 century. About 4 weeks ago the passenger side AC was very cold while the drivers side was hot. Now it's not blowing cold air on either side. Has anyone fixed this problem? Pleae let me know.

I'm going to replace the cabin air filter, it hasn't been replaced yet. However I don't think this would fix the warm air problem I'm having.

Thanks

I just corrected the lack of A/C for the driver's side on my 98 Buick Century I just bought. Turns out that I was just low on a refrigerant charge. I had only a 1/2 lb of refrigerant left in the system, therefore it only blew somewhat cold out of the passenger vents at 58 degrees. After having my A/C system evacuated to eliminate moisture and recharging the system to 2 1/4 lbs of refrigerant, both driver and passengers vents blow cold air at 40 degrees now. So don't assume the temp doot to the driver's side is stuck or not functioning at first glance. If you turn the temp knob to heat postion and it blows hot air, chances are that the sensors and the temp door are functioning okay along with the control head. So try having the A/C charge checked first before going further.. Also the temp doors to allow heat or cold air through the cabin outlets are not vacum operated, yet are actually small electric actuator motors that open & close the temp doors when signalled by the control head unitbased upon imformation supplied by on board sensors.

have a 98 park ave ultra with dual heat & a/c. Only getting cold air on the passenger side and hot on the drivers. Has anyone found the cause for this yet?

have a 98 park ave ultra with dual heat & a/c. Only getting cold air on the passenger side and hot on the drivers. Has anyone found the cause for this yet?

Sorry but please do not resurrect old threads. Threads over 3 months old.

I recommend starting a post at Park Avenue or you may start a new one here if you feel an inadequate answer will be provided. Thread closed.