Air-Conditioning Charge Up ?

[Eighty8LX50]

I was trying to charge my ac system on my car today and it did not seem to work ! I bought the $15.00 r-12 to r-134 retrofit kit. It took the first oil charge can, but the compressor was not turning on or cycling. No air was blowing cold still after that. Is there some kind of switch for the compressor to turn itself off when its gets low on freon ? Or is this compressor shot ?

 

[66 Tiger]

Do you know if the compressor worked before you did the retrofit?

 

[Eighty8LX50]

Do you know if the compressor worked before you did the retrofit?

I just bought the car and I am just finding out its problems, I never heard the compressor turn on before, but was trying to see if it would kick on with a charge.

 

[larrendeuce]

Before you add any oil or refrigerant you need to vacuum out whats left of the old stuff.

 

[Hawaii-50]

There is a switch on top of the accumulator called a clutch cycling switch. It costs like $20 from the parts store and you can change it pretty easily. I charged mine up with R-134 and it worked like a charm-only because I had a shop do the conversion, which included vaccuming out the R-12 as was previously suggested. Last summer in Florida my vent temps dropped from 70 degrees before the recharge to 35 after the charge.

Later-
Hawaii-50

 

[tom2001gt]

If it is low on freon or has no freon the compresser won't turn on. My compressor was left open for over a year and it worked after I vacuumed out the system.

 

[jrichker]

See http://jrichker.stangnet.com/Mustang_tech/R134a_conversion/R134a_conversion.htm for R134a conversion help.

 

[Eighty8LX50]

See http://jrichker.stangnet.com/Mustang_tech/R134a_conversion/R134a_conversion.htm for R134a conversion help.

Thanks to this info & other I have solved my problem, Its the switch for the acumulator, Today I put a jumper wire on the harness connector that goes to the switch and then the commpressor started cycling Then I charged it with a stop leak and leak detector just to be safe, Then charged it with a can of R134 Freon. The air then Blew COLD ! Very Cold ! Then I tryed reconnecting the pressure switch clip and the compressor would not cycle anymore. So my question is do I have to evacuate the system before changing the switch out? I think I do. The ac system works great now with the jumper wire connected - I guess I will leave it on for now. Maybe more R134 will make the switch work ?

 

[jrichker]

The pressure switch has a schrader valve in it like the other A/C connections. You don't have to do anything with the refrigerant to change the switch. It just unscrews and doesn't let much gas leak out.

 

[gsalisbury]

I have the same issue with my 2000 and replaced the switch atop the acumulator as well. Running a jumper wire yielded the same results. I had taken the car to my mechanic and all he did was top off the system and it works fine. I asked him what I did wrong and all he did was laugh. Cost me $60.00 but the system is working like a charm.

 

[daleclough]

I was trying to charge my ac system on my car today and it did not seem to work ! I bought the $15.00 r-12 to r-134 retrofit kit. It took the first oil charge can, but the compressor was not turning on or cycling. No air was blowing cold still after that. Is there some kind of switch for the compressor to turn itself off when its gets low on freon ? Or is this compressor shot ?

Where did you get the kit and what did it include?

My A/C needs a charge (engine swap before I bought it and never recharged). I'd rather try this before dropping 10X as much with a shop.

 

[glowstang93]

Here is a link to the a/c low pressure switch install the I did last week. Very easy, about $13.00 for the switch. Just an fyi, I got a bad switch on the first one that I bought. http://forums.stangnet.com/showthread.php?t=705606

 

[88 Fox GT]

Yes your low pressure switch is definitely bad. Mine cost me about $18 to replace. Not very expensive.

 

[jrichker]

The low pressure cutout switches are adjustable. They should be set with the low limit about 18-21 PSI, the stock setting is about 25 PSI. Remove the wiring connector and there is a screw slot in between the connector pins. Turning it clockwise increases the trip pressure where it cuts off and counterclockwise decreases the trip pressure. I believe that each 1/4 turn counterclockwise lowers the cutoff pressure by 1 PSI.