1998 Park Ave HVAC blows cool/warm air on the drivers side and cool/cold on the pass.

[210010243]

There are several threads here that cover a part of this message; However I will continue with my problem.

The driver's side HVAC Blows warm/cool air while the passenger side.

I have removed the Blend door actuator and moved the door by hand. In one direction it provides Hot air and in the other warm/cool.

I have removed, cleaned out the Cabin Air Filters/housing and removed the Blower Motor and cleaned that area also.

The coolant charge is correct.

Through the use of a Boroscope/Camera my mechanic has looked into the ducs searching for any obstructions and have found none,

At this point we are at a lost as to what can be wrong and before we tear the dash apart to remove the HVAC unit, I am asking for your assistance, if any of you have had an issue such as this.

 

[HotZ28]

If all blend doors are doing their job as designed, more than likely the compressor is not doing it's job. The V5 compressor has a variable control valve that varies compressor stroke based on demand. The system pressure should be tested at 3K rpms with A/C in Max fan to determine whether it is an compressor/control valve problem. The low and high pressures should be within 30 psi of each other.
http://www.tx2.westpointaog.com/Refrigerant_Control_Valves.pdf

You can purchase a new DELPHI Part # CS20009 compressor from RockAuto for $169.79. Of course you would need a new orifice tube/expansion valve, accumulator/drier to get the compressor warranty. The system would require proper evacuation, flushing and evacuation to work properly, and maintain warranty.

 

[TheCapnVideo]

This may not work on the '98 but it is worth a try before tearing down the dash.
Some cBuick control systems (I do not know if it was so before 2001) default their logic to OFF. If you had your hvac controls in any position other than "OFF" when disconnecting a battery you may have a situation where all flapper positions are relative to that setting.

Shut your HVAC OFF meaning fan and air direction. disconnect your battery for a few HOURS (5-8) I say hours because I know from experience that a few minutes did nothing and 3 hours wasn't enough but overnight worked.

Re-connect your battery and your HVAC system will 'boot' the vacuum servos from "OFF."

I had the same issue and did tear the dash apart.only to find nothing. Everything worked 'properly' just not in the right sequence, killing the vacuum and computer's HVAC setting allowed everything to sync back up all by itself.

 

[Buick Boy]

Hi there, I just had to work on my dad's '99 Regal GS and there is a GM bulletin on those pertaining to this exact problem. The solution for this car is replace the HVAC Controller in the dash. This is only for cars with the RPO code CJ2, which is auto climate control. I am not positive this bulletin applies for the Park Ave, I will try and get ahold of my dad, he has the printed bulletin.

 

[Buick Boy]

PS Try the Capn's fix of disconnecting the battery before trying the HVAC controller!🙂

 

[210010243]

Thanks to all for your suggestions, the car is now at my mechanics and he to have not been able to determine what the problem is.

I will share your input with his as I don't think he will be able to solve.

So keep your suggestions coming and I will try them all until we get this solved.

For the record the HVAC on the 1998 Park ave is electrical, with no Vacuum

 

[210010243]

I would like to thank all that replied and gave me their insight on how to solve my problem.
I took HotZ28's advice and replaced the compressor; which was my first choice when I began to try and fix this problem. the compressor had lost it's charge over the winter and I gave it a quick charge to get it going.

Replaced the compressor and associated components and the system is working much better, there is a slight difference in measured temperature (the drivers side is 8 degrees lower than the Passenger side) out of the upper vents. While this is not what I want, I will live with it.

Again thanks to all for your advice and a personal thanks to you HotZ28.