A/C not cold

[GTPNovak]

Not sure if this is the right area or not.
2000 GTP (68k sat for a while) with dual climate control. Econ button instead of A/C button. System pressure is 35 psi when running and compressor clutch is engaged and stays engaged. Passenger side blows slightly cooler then drivers. Checked the blend door actuator on passenger side and is functioning.

Not sure what to try next. All the searching i have done leads to the hvac controller but it seems to be working correctly based on the actuator responding to the temp control knob and the buttons change as they should.

You guys have any ideas?

one thing that seems weird is the fuse box. the hvac controller fuse location was empty and has only one fuse lug. i am guessing that is for cars without the divers information center and the ones with them get the hvac power from the drivers information center.

Thanks for the help.

[J57ltr]

You need to check the high side pressure too. But unless it's in the 50's to 60's when your pressure shouldn't be that low. you should be at least 45 and on Max AC (Fan on high set to recirculate) and the car interior hot it should be in the 45/240 range as the interior cools or if you try it at night when it is cooler, you may see the high side pressure drop to about 150, most GM cars since the late 90's use a variable displacement compressor pump so there is no need for cycling. I am not sure which ones have it and which don't, but the one in my 05 GTP is and so was the one in my 97 PA. Not real sure on 00 GP but another one I looked at did use the variable displacement pump I just don't remember the year. Usually what happens with these (if they don't fail in the normal modes) is that the valve gets stuck on low displacement and while you are cruising down the road it's fine, but sitting in traffic it will start getting hot in the car.


Jeff

[GTPNovak]

Thanks Jeff, Looks like i will try to add some R-134a and see if that helps.

[GTPNovak]

Added a can of R134A on sunday and its is working now. But driver side is warmer then passenger. I will need to check the blend door on the driver side since i only verified the passenger side was working so far.

[bonerjamz03]

How much 134a did you add? These systems hold something like 36 oz. of refrigerant (might want to double check that) so if it was only a 12 oz can you may need to add more.

[GTPNovak]

I only put in 12oz, but remember i had 35 psi before adding. I can check the pressure again but i am pretty sure i was at 45 psi and passenger side blows cold. Driver side is just slightly warmer which is why i am thinking blend door issue.

[J57ltr]

I never really go off of weight unless it's a complete evacuation, and even then I still use the gauges to see what's going on. I have seen systems that are low have a slightly warmer output on one side and have also seen that with a blend door that's not seated all the way. I would check both blend door actuation and make sure you are looking at your high side pressure too so you can make sure you don't have an obstruction in the orifice tube or something.

Jeff

[GTPNovak]

How much 134a did you add? These systems hold something like 36 oz. of refrigerant (might want to double check that) so if it was only a 12 oz can you may need to add more.

After overthinking the whole thing (always do this as an engineer) I added a second can of R134A and now it blows ice cold on both sides.