pontiac grand prix a/c problems

[randywright]

I bought a 1999 Pontiac Grand Prix 3.8 Supercharger with dual air condition. The passengar side blows colder than the drivers side. Both sides are set to the lowest temp, the freon is good. What could be causing the problem, Thanks.

[brcidd]

How do you know the "freon is good" ??

There is no way to know how much there is in the system- until you extract and weigh it--you could be running at less than half of specified amount and the variable compressor (that never cycles) will try to compensate and show pressures that look "good" based on low side death kit gage only -- so based on the 3000 or more V-5 systems I have analyzed- my money is on the low charge scenario...

The number one cause of your complaint is loss of charge due to a leak-- number one leak location on your Variable stroke compressor is at the compressor shaft seal---

The passenger side of evap is first to cool and that is why the driver's side is warm....

[randywright]

Thanks

[BNaylor]

GM has a TSB on this issue. Since your GTP is used and maintenance history probably unknown you could have a leak or it may be undercharged with refrigerant (R134a). The effect is felt mainly in high temperature and high humidity conditions. The passenger side being colder than the driver's side.

Look at the data label located on one of the strut towers. The data label probably shows 1.88-1.9 lbs as refrigerant capacity. What GM has claimed is that would create an undercharge situation and the label was erroneous. They now recommend putting in 36 ounces or 2.25 lbs of R134a.

Also it would help to post whether you have the manual dual zone or CJ2 ACC - automatic climate control systems.