1999 Grand Prix A/C

[hagglerock]

I believe my unit is just low on freon but would like to confirm. Does anyone know the correct method to jumper out the pressure switch to see if the compressor clutch will engage. My switch is a three wire unit.

Thanks in advance

[BNaylor]

The problem with jumping out the pressure switch is it is a low and high pressure switch. Therefore, the jumper will have to include a resistor representative of normal pressure to fool the PCM into turning on the compressor. Best thing to do is check the pressure at the low pressure port. If real low based on ambient temperature just recharge using one can of 134a. Once sufficient charge is established the compressor should start cycling without having to run the jumper.

[edbrycem]

Originally Posted by bnaylor3400

The problem with jumping out the pressure switch is it is a low and high pressure switch. Therefore, the jumper will have to include a resistor representative of normal pressure to fool the PCM into turning on the compressor. Best thing to do is check the pressure at the low pressure port. If real low based on ambient temperature just recharge using one can of 134a. Once sufficient charge is established the compressor should start cycling without having to run the jumper.

make sure u r allowed to do your own a/c charging. Here in Wisconsin its illegal w/ a hefty fine if u r caught w/out a license charging your system. but in minnesota u can buy it off the shelf in walmart, so states vary. my 99 leaked over the winter, iguess the 134 is thinner then the older freon so when it gets cold it often times leakes out of the seals. FYI, thats all, i'm bored

[BNaylor]

Originally Posted by edbrycem

make sure u r allowed to do your own a/c charging. Here in Wisconsin its illegal w/ a hefty fine if u r caught w/out a license charging your system. but in minnesota u can buy it off the shelf in walmart, so states vary. my 99 leaked over the winter, iguess the 134 is thinner then the older freon so when it gets cold it often times leakes out of the seals. FYI, thats all, i'm bored

It is not illegal in Texas to purchase R134a and do your own recharge. He lives in Kentucky. Yeah those eco rules in green states are a trip.

[SNKPWR]

you can purchase r134a and recharge your own system in kentucky...

[tjaygrid]

I bought a R-134a recharge and cannot get the quick connect to fit either port on my 1999 Pont. Grand Prix. I know you are supposed to perform on the lower port, but is too big. The other port is too small.

[BNaylor]

Originally Posted by tjaygrid

I bought a R-134a recharge and cannot get the quick connect to fit either port on my 1999 Pont. Grand Prix. I know you are supposed to perform on the lower port, but is too big. The other port is too small.

The low pressure port is located at the firewall so try there. There is a blue cap on it. Some of those recharge kits and quick connect couplers are cheap.