Air Conditioner Problem

[hillre]

HELLO, I've a 1996 Grand Prix SE 3.1 with 233K miles. Having problems with air conditioner. The problem is that i can't get it to charge. It won't accept any freon. I've been told that it could be a blockage in the system. Is there a way to unblock the system without taking it to a shop. Is there a product out there that a DIY can do at home. Just curious! The local shops are quoting me one hundred twenty dollars plus to service and charge the system. I would appreciate any assistance that anyone could provide. Thanks

[BNaylor]

How low is the charge? There is a pressure switch. Is the compressor kicking in? Until it does there is no suction so the system will not take any refrigerant.

[hillre]

The pressure is now zero but was 36 pounds plus. The system was believed to be overcharged and wasn't blowing any cold air at all but the compressor was kicking in. Decided to have all freon removed but now, the problem is still the same, can't add any refrigerant, none. It seems like the system has no suction at all even after having it discharged. What possibly could be wrong with the system other than a blockage? If so, can this be fixed at home? Thanks for responding!

Originally Posted by BNaylor

How low is the charge? There is a pressure switch. Is the compressor kicking in? Until it does there is no suction so the system will not take any refrigerant.

[BNaylor]

You'll have to run better A/C diagnostics to get to the root of the cause. Are you using decent A/C manifold pressure gauges and a general A/C repair guide with the A, B, C, D charts? What did the high pressure (discharge) read? You'll probably have to force compressor engagement by jumping the AC clutch relay or get 12 volts to the clutch somehow to take the refrigerant.

[brcidd]

Typically the charge will all go right in (without even starting the car) after a good vacuum is pulled on the system-- your low side port may not be opening when you turn the valve to open it-- I would double check that....

[hillre]

I'm using pressure gages that i purchased at auto zone as i have always used since learning how to add freon to a system. I don't have a general A/C repair guide nor any charts? Where do i get an ac repair guide/charts? I'm somewhat a novice so i don't exactly know what you mean by "high pressure discharge" reading. I think i had just better take it to a local shop since I'm not really experienced at testing an a/c system. Thanks anyway for the assistance.

Originally Posted by BNaylor

You'll have to run better A/C diagnostics to get to the root of the cause. Are you using decent A/C manifold pressure gauges and a general A/C repair guide with the A, B, C, D charts? What did the high pressure (discharge) read? You'll probably have to force compressor engagement by jumping the AC clutch relay or get 12 volts to the clutch somehow to take the refrigerant.

[hillre]

How exactly do i determine if the low side port is opening? If not, is it difficult to replace it? Thanks

Originally Posted by brcidd

Typically the charge will all go right in (without even starting the car) after a good vacuum is pulled on the system-- your low side port may not be opening when you turn the valve to open it-- I would double check that....

[brcidd]

When you attach the low side gage and open the valve- you will see the gage move up if there is pressure in the system and there is communication to the gage- that way you know the gage is reading system pressure....

[BNaylor]

That is assuming he is using an A/C manifold gauge set with the control valves at the head unit and at the service port connectors. He is probably just using the typical DIY cheapy refill kit with the recharge hose and flaky gauge.

And I seriously doubt it is a ACR 2000 shop set and he probably does not individual capacity to properly evacuate or pull vacuum.

[brcidd]

Sorry- I have trouble envisioning using the cheapo gages-- I have no experience with cans and Wally-world refill kits- but still the system should equalize from the can to bring up the pressure as the charge goes in- if the low side port is opening with the cheapo adapter- If all charge is gone- I would strongly recommend a vacuum should be pulled first- no matter how you do it-- even renting a vacuum pump- or borrowing one. Also, he may have to lean on the depresser some to open the schrader.....

[BNaylor]

I agree if the system is totally discharged vacuum not only should be pulled but must be done.

Equalize? Possibly but based on my experiences you can get into some weird situations trying to charge an A/C system with the Delco Harrison V5 variable displacement compressor without it running and the way the pressure switches work. Another option is to dump the full weighed/measured refrigerant charge right into the high side which you can do with the compressor not running. It will be in a liquid state. However, not recommended for the average DIY person without proper A/C shop equipment. To start you'll need a manifold pressure gauge set which is the best way to dispense refrigerant even for the typical DIY person. But the key is you have to know what you are doing and that comes from proper training and experience.

[hillre]

Thanks very much for the assistance. I've decided to take the vehicle to a local shop due to inexperience with vacuuming/testing a/c systems. Take care!

Originally Posted by BNaylor

I agree if the system is totally discharged vacuum not only should be pulled but must be done.

Equalize? Possibly but based on my experiences you can get into some weird situations trying to charge an A/C system with the Delco Harrison V5 variable displacement compressor without it running and the way the pressure switches work. Another option is to dump the full weighed/measured refrigerant charge right into the high side which you can do with the compressor not running. It will be in a liquid state. However, not recommended for the average DIY person without proper A/C shop equipment. To start you'll need a manifold pressure gauge set which is the best way to dispense refrigerant even for the typical DIY person. But the key is you have to know what you are doing and that comes from proper training and experience.

[hillre]

Thanks for your assistance. I decided to take the vehicle to a local shop for proper testing and to get a system vac if necessary. Take care!

Originally Posted by brcidd

Sorry- I have trouble envisioning using the cheapo gages-- I have no experience with cans and Wally-world refill kits- but still the system should equalize from the can to bring up the pressure as the charge goes in- if the low side port is opening with the cheapo adapter- If all charge is gone- I would strongly recommend a vacuum should be pulled first- no matter how you do it-- even renting a vacuum pump- or borrowing one. Also, he may have to lean on the depresser some to open the schrader.....