1998 Pontiac Grand Prix GTP
I have 5 vents on the upper dash board. I will count them from the passenger side
starting with #1.
With the AC on #2 upper dash vent is the only one providing cold air. I must have a
damper not working somewhere. The other vents 1-3-4 and 5 have the same volume of
air but it is ambient. #2 provides cold AC air.







JK:
Sounds like you may have 2 problems.

Two common causes for the right side vents being cold, and the left side warm....

1) The drivers side temp door actuator motor has failed. This would cause both right
side vents to blow normal, the drivers side vents to blow warm.

2) Low freon charge. This would cause 1 or both of the right side vents to blow cool-
but not as cold as they should be.

There is no damper between the 2 right side vents. They are from the same plenum.

This is why you may possibly have a low freon charge, and the drivers side door motor
faulty.

I would suggest getting the freon charge checked. Not just the pressure, but actually
remove and have it measured. Even a 1/4 - 1/2 lb. can cause rt. side to be cool only.

Get the freon charge correct, then see is the drivers side vents are still warm, then you
probably have a door motor gone bad.