A/C Troubleshooting

[theboogins]

1044642

94 Grand Cherokee Laredo-all of a sudden a/c quits, blows hot air, a/c dashlight light, fuses check out, but compressor does not operate. I hooked up an a/c pressure guage to it-reads zero. Clutch will turn by hand, no apparent sign of damage or major leak.



What can I check? If I open a car of 134 and connect it to the inlet, I guess nothing will happen unless the compressor is spinning right?



Help Please.





thanks.



J. Boggs[addsig]

 

[XJNick]

1044647

Does the A/C ever blow cold air? It could still be an electrical problem. You will get a pressure reading on both the High and Low side regardless of if the compressor is running or not. When the compressor is turned on the High side reading should go up and the low side reading should go down. When you add refrigerant to the system, you ALWAYS add it to the low side port (which may have a blue cap on it). If the system runs and gets cold, then quits, the pressure could be building to high, indicating a restriction in the system. This is just some basic info, if you have a leak things get more complicated.



A good Auto A/C knowledge base is http://www.aircondition.com, and D's tech pages. Hope this helps[addsig]

 

[dingus]

1044694

from the sudden drop of pressure, it sounds like you busted something somewhere along the line. (leak) has this thing seen any sudden smacks or impacts recently? a shop will be able to do a vacuum test and find the leak pretty quickly if you wanna shell out some money.[addsig]

 

[MudderChuck]

1044748

Sounds like a leak to me, double check your gauge and connector by squirting a little refrigerant out of the low pressure side (larger tube) being careful of your eyes. If there is no pressure at all you have a leak. Refrigerant is (most systems) mixed with oil and will leave a stain where it leaked out. Usually a stone into the radiator (heat exchanger, condensor) at a joint or connector, where the tubing rubbed against some sheet metal or the front seal on the pump (behind the pulley and clutch). A flahlight and careful thorough inspection will usually find the leak. If you need some tips on repair, I can help some. Seem to remember Jeep using "O" rings at some of the couplings, that have a history of leaks.[addsig]