I recently recharged my a/c with refrigerant, and the pressure is perfect - however, when I blow the a/c at max, I get semi-cool air coming out of the passenger vents, and warm air coming out of the driver side.

I DO NOT have a climate-control system, it's just one temperature setting for the whole car.

One thing I noticed when I attached my low pressure gauge to the service valve is that with the a/c off, the pressure read dangerously high, and when I kicked the a/c on full blast, it then gave a normal reading.


What I would like to know is how to tell if the compressor is running, and any opinions as to why only half of my dashboard vents blow cool air.

The readings without the A/C on are normally irrelevant. To properly diagnose your problem you'll need to check high and low pressure, especially if you want to determine you have a bad compressor. By looking at the two readings you can most likely tell if the compressor or some other part like the expansion valve, condensor, evaporator, accumulator, etc is the cause. You should be able to hear the compressor clutch click or clunk when you turn the A/C on.

On the A/C control side some uneven cooling problems could be caused by a defective blend door or temperature actuator but that is most common on dual climate control HVAC systems.

I recently recharged my a/c with refrigerant, and the pressure is perfect - however, when I blow the a/c at max, I get semi-cool air coming out of the passenger vents, and warm air coming out of the driver side.

I DO NOT have a climate-control system, it's just one temperature setting for the whole car.

One thing I noticed when I attached my low pressure gauge to the service valve is that with the a/c off, the pressure read dangerously high, and when I kicked the a/c on full blast, it then gave a normal reading.


What I would like to know is how to tell if the compressor is running, and any opinions as to why only half of my dashboard vents blow cool air.

I sure hope you did not ue one of them NO NO Kits.
What kind of freon did you use?
Post back your low and high side readings with comp on and at Idle and at 2K RPM

Wal Mart DEATH KITS

You cannot properly and safely recharge an air condition system with them.

The one side stop and go gauge does not tell you what your system is doing or is over charged or undercharged.
A overcharged or malfunction air condition system can reach over 500 lbs of pressure.
Enough to blow up that can or system and freeze you at first and the burn you or blind you and if any propane /butane in there blow and light you up.

The stop leak crap and who knows what kind of oil in the kits there will stop your system for sure.
Just like pouring super glue in it.
And some kits even contain freon with a butane mixer.
Good for a big blast.

If you are going to do it do it right and safe.
Here is what you need to start with.
http://www.ackits.com/merchant2/merchant.mvc?Screen=PROD&Store_Code=AMA&Product_Code=66773

In the older days you could just throw in a can and go.
But over the years just adding freon is getting harder to do.
Newer systems have to have the correct amount of freon down to the ounces.
Most will need pumped down and vacuumed down and the right and amount of oil and a set amount freon charge installed to get the air to cool right and the system to last.
If an air condition is low there is usually a leak that needs fixed and also a lose of lubricating oil from system.
Also air and moisture enters a low system
If you are going to try to do it get the proper type air condition gauge set with the low and high side gauges.
Hook up the gauges and get a reading with compressor running at idle and at 2000 rpm on the high and low side.
Post back pressure reading and we can help you.
MT

If you don't use your A/C all the time, you may have mildew buildup on your evap core, essentially blocking airflow through it. The seals around the evap core may have failed, allowing air to go around instead of through the evap core. The higher the fan setting, the warmer the air, as a stronger force will push around the seals, where a lower setting may still pass through the evap core. On MAX, the system is recirculating air from inside the vehicle, instead of taking fresh air from outside. This routes air differently through the HVAC box, which may be the reason for your problem.

MT2500,

That info sure looks familiar.

Wal Mart DEATH KITS...lol. :lol: AZ has them too.

MT2500,

That info sure looks familiar.

Wal Mart DEATH KITS...lol. :lol: AZ has them too.


10-4 on that bnaylor
I may have to reword it some.
I wish I know how many air cond systems it has killed?
MT

10-4 on that bnaylor
I may have to reword it some.
I wish I know how many air cond systems it has killed?
MT

Lol. :lol: Killed? None to my knowledge. Good work!

My 97 is doing the same thing. I know there is something stuck in the duct but I can't get it out. My right side vents blow very cool air, driver side is warm or ambient temp. Also the A/C condensation is leaking inside on the floor of passenger side. What causes this?? I really do not want to pull the dash. I don't mind working under the car or under the hood, but I hate working under the dash.

i have the exact same problem on my 97 gt too, also it is hard to even notice the air is on until i crank it to 5 or max, 1-4 is very weak. i read the above statements but what is the best way of finding/solving tthis problem?

i have the exact same problem on my 97 gt too, also it is hard to even notice the air is on until i crank it to 5 or max, 1-4 is very weak. i read the above statements but what is the best way of finding/solving tthis problem?

If the blower speed is OK in position 5 (hi) and weak in 1- 4 then you have a blower motor control problem. Probably a flaky blower motor resistor (BMR) if you have a manual HVAC and blower motor control module for digital climate control. It does not sound like a problem with the actual A/C cooling.

If the blower speed is OK in position 5 (hi) and weak in 1- 4 then you have a blower motor control problem. Probably a flaky blower motor resistor (BMR) if you have a manual HVAC and blower motor control module for digital climate control. It does not sound like a problem with the actual A/C cooling.

I understand what he is saying about the weak air flow, mine is doing the exact same thing. I don't think its the blower motor. The blower motor is fine on all other settings. I think recirculation vent isn't closing all the way when you turn it to MAX. I'm getting outside air coming through. Bob do you have any idea why the A/C condensation would be draining into the car. If I run my A/C on my hour ride home I have a nice puddle of water on the floor board of the passenger side. The GTP is being rode hard and is getting put away wet.

I understand what he is saying about the weak air flow, mine is doing the exact same thing. I don't think its the blower motor. The blower motor is fine on all other settings. I think recirculation vent isn't closing all the way when you turn it to MAX. I'm getting outside air coming through. Bob do you have any idea why the A/C condensation would be draining into the car. If I run my A/C on my hour ride home I have a nice puddle of water on the floor board of the passenger side. The GTP is being rode hard and is getting put away wet.


Have you removed the kick panel to see where the condensation/water is coming from? If it is from the blower motor area or in the lower part of the HVAC assembly then I'd check to see if the drain hose is mounted and routed correctly. The water should be channeled to the drain that goes into the firewall and vent to the outside. See drain hose in pic below.

On the flapper that closes in MAX or Recirculate you can remove the plastic cowling at the bottom of the windshield and inspect it on the passenger side of the intake duct. Don't know if you have a cabin air filter but at that port a vacuum actuated flapper extends to close that area off. In vent or normal A/C or heat it should be open.


http://i5.photobucket.com/albums/y186/lizzywiz/gpblower.gif

OK, an update.

First off, YES, I recharged my A/C with a simple can and a low pressure gauge - did it after reading suggestions on this message board, in fact. Now I hear that was a wrong thing to do. Whatever. I'll submit to a beating for my stupidity.

My problem is such - I know my A/C system is working fine. Sometimes I get cold air. But I think I have an electronic actuator that's bad, that controls where the vents get their air from (i.e outside air, or recirculated a/c air).


Pontiac service department tells me the actuators are located under the dash, central position, and I can check them with a multimeter...?

OK, an update.

First off, YES, I recharged my A/C with a simple can and a low pressure gauge - did it after reading suggestions on this message board, in fact. Now I hear that was a wrong thing to do. Whatever. I'll submit to a beating for my stupidity.
..?

Better to use one with gauge but no beating forthcoming from me.

OK, an update.

First off, YES, I recharged my A/C with a simple can and a low pressure gauge - did it after reading suggestions on this message board, in fact. Now I hear that was a wrong thing to do. Whatever. I'll submit to a beating for my stupidity.

My problem is such - I know my A/C system is working fine. Sometimes I get cold air. But I think I have an electronic actuator that's bad, that controls where the vents get their air from (i.e outside air, or recirculated a/c air).


Pontiac service department tells me the actuators are located under the dash, central position, and I can check them with a multimeter...?

If you are getting cold air on one side but not the other of a manual HVAC system without dual climate control checking the temperature actuator with a multimeter could be an exercise in futility because there is only one. If you are having a problem with air flow/direction within the heater/evaporator assembly it could be other things but disassembly may be required which is not fun.

Isnt it possoble that one of the tubes/ducts, that feed the vents that are not working, couldnt it hav fallen off ?

Isnt it possoble that one of the tubes/ducts, that feed the vents that are not working, couldnt it hav fallen off ?

Good point Xero but he does not have airflow problems. It is just that typical warm air driver's side and cool air passenger side which is common on a Grand Prix but more so with dual climate control. He does not have dual. Normally uneven cooling across the evaporator core is low refrigerant charge but he claims that is OK.

Also, the evap core has a big seal firewall side that can deteriorate allowing hot air from the heater core to get into the ducts/air channels.

Normally it has to be torn apart for further inspection.

:uhoh:
OK, i see what youre talking aboot now, letting in fresh air.
I hav replaced that seal for the evap, but I hav never had the H core or evap totally disassembled and out of the car though.

But ya, hav fun taring it apart :thumbsup: