DenissK

98 GT

So recently I've been noticing that my car does not cool down when driving with AC. I put it on max and I can feel it blow cold air but it is still fairly stuffy in the car. I bought the recharge kit with the gauge. With AC set up on max and compressor clutch spinning, the gauge reads 35 PSI. It tells me to "correct refrigerant charge".
Now, I live in the South and my daily ambient temp is around 80 degrees. As far as I have read online, my PSI should be around 45, can anyone confirm this? I don't want to overcharge it and cause damage.
I replaced my AC compressor a year ago and did all the vacuuming procedures before putting the refrigerant. I hope I just need to add some more for it to cool the car properly.

dawson1112

Living in Fla I bet you have a lot of dead bugs in your condenser. Cleaning it out will help it to get rid of the heat better. Make sure you dont have a small vacuum leak behind the glove box where the vacuum reservoir for the HVAC controls is located, or under the hood where the vacuum line for the HVAC enters the cabin. Also how old is your battery? A weak battery will cause the radiator/cooling fan to run slower. My 99 lincoln, battery went bad and it caused my air bags to not pump up fully and also my ac was not able to keep up in the south texas heat. I noticed a huge difference in the ac after I put a new battery in.

DenissK

So I just added some refrigerant so that I have 45 PSI. Did not seem to help much. I also noticed that my passenger side vent is not blowing as hard as the central and driver's side vents. I've never bothered to check how hard each vent blows so I can't say if that's how it was before.

Urambo Tauro

Try closing other vents to check each vent's airflow individually.

Also, are you turning it to MAX AC right from the start? You'll get better results if you use VENT for a minute with the windows open to expel hot air. After that, you can push more warm air out as the AC starts to cool the car by turning the **** to NORM AC with the windows partially closed. Give it another minute, then crank it to MAX AC and shut the windows. That will keep the cooled air inside the car as the AC continues to cool it.

DenissK

I tried closing one of the central vents and the passenger side vent would blow slightly harder but not as hard as the other ones. Yes, I usually put it on MAX AC from the start to get the max cold air and then switch it to normal. I will try your technique.
Also, I noticed that my AC clutch is always engaged regardless of the AC settings (norm or max). Somebody suggested looking at the fuses. I am not sure how that is connected though.

Derf00

Get a thermometer and see what the vents are registering. It should be in the 35F to 42F depending on ambient temps. Also, only getting a low side reading (that little gauge that comes with the refrigerant) is pointless when troubleshooting an AC system . You need manifold gauges to see what the low side AND high side are doing pressure wise.

DenissK

So I got the manifold gauges. I got 45 PSI low side and 275 PSI high side in 87 F weather. I was told that both sides are too high, especially the high side. Basically overcharged. I discharged some refrigerant to lower the pressure but even with the low side being within the norm 35 40 PSI, the high side is still around 250 PSI. Do you think I may have an obstruction in the system?