Pontiac Repair: a/c vents, single zone, control cars

Question
QUESTION: I have a 1997 Grand Prix GT 3.8L V6.  I just had the freon recharged after some repairs I had my shop do.  Now the driver's side is blowing warm air and the passenger side cold air.  Could it be the directional door (as I read on a post with the opposite problem)?  If so how can I fix this myself?

ANSWER: Hi Chri:
Well it can be 2 things either the actautor for the temp door is broken and it's pretty east to fix just three screws hold it on to the side of the heater box. Or the system is under charged. I have seen that a bunch of times on thes older dual temp control cars. I would first check that the proper amount was put into the system and not just a "guess" as to how much was added and then go from there. good luck :)


---------- FOLLOW-UP ----------

QUESTION: It has a single temp control not dual.  Not sure if that would make any difference?  I don't pretend to be a car guy so forgive me for asking...how/where do I access the heater box to check the actuatork?

Answer
Hey chris:

If this is just a single zone system and the vents are warmer on the driver then the passenger then I for sure would take a look at the charge in the system It's not a issue with a temp door. the same dor controls the whole box. It has to be a regregeranet charge issue it's not an air flow issue in the heater hox. Like I said the system charge is critical on these cars so adding an approx. amount of a charge is not goos enough. It needs the exact amount to work correctly.