Air Conditioning Question

**ryan88z** · 04-09-2008

I have a 99 Grand Prix 3.8 SC I bought the car recently and noticed the ac wasnt working.
There was no freon in the system but i didnt think anything of it because i the motor was replaced before i got it so i figured they just never filled it up. i filled it up with freon, couldnt get the compressor to come on so i jumped it on the relay to engage it. 'with it on i still dont get cold air and i know there is freon in there. any suggestions

**SyntheticShield** · 04-09-2008

Well Im not AC expert, so take it with a grain of salt, but do you have enough refrigerant in there? If you think you do, I wonder if the low pressure switch is bad?

**ryan88z** · 04-09-2008

yea i do have enough freon in there believe me i made sure of that . ive made that mistake b4 thanks for your input

**SyntheticShield** · 04-09-2008

Is there a way to bypass that low pressure switch to make sure its good? Just tossin a few things out there hoping they help.

**02BlueGT** · 04-09-2008

Is there an obstruction in the system? Did you vacuum out all the moisture before you filled it, cause a lot of moisture and the AC wont cool effectively.....

To get all the air out, the system must be put into a vacuum to lower the boiling point of water to room temp, then it ends up vaporizing and being sucked out by the vacuum pump, this can take hours but must be done if the system was left open or discharged for a long period of time

**Zef_66** · 04-10-2008

How did you fill the system? With the cans? Or with an AC machine?

If there is a leak in the system, the freon could leak out just as fast as you put it in. Best to have the system leak tested by pulling a vacuum on it. This will also remove any moisture from the system and help everything work top notch. If you really want to make sure things are up to par, you can change the accumulator and orifice tube. Then have a vacuum pulled, and filled with the correct amount of refrigerant by weight.

**archemedes** · 04-10-2008

Originally Posted by Zef_66

How did you fill the system? With the cans? Or with an AC machine?

If there is a leak in the system, the freon could leak out just as fast as you put it in. Best to have the system leak tested by pulling a vacuum on it. This will also remove any moisture from the system and help everything work top notch. If you really want to make sure things are up to par, you can change the accumulator and orifice tube. Then have a vacuum pulled, and filled with the correct amount of refrigerant by weight.

exactly right, also are you sure the compressor is good?