Why didn't anyone tell me that the guages are to have the valves screwed shut to get an acurate reading? LOL, My 95 Lincoln has a reading of 0 on the low side and 100 on the high side, the manual says it should be Low 22-47 and the high should be 160-245. My other car not a lincoln but still need help is a 95 T-birds pressuer is Low side 25-50 guage jumps back and fournth with compressor coming on, and 75-100 on high side guage jump back and fourth with compressor running. The manual says it should be Low side 25-50 and High side 75-100. Any help is greatly appreciated. I think I might be able to do this myself if I have help. Please, I have a lot of free time now that the economy is so crummy.

 

You can't just go by the between HERE and HERE pressure specs. The pressures are affected by the ambient temperature on the HIGH side and the operating temperature of the evaperator on the LOW side. Combined together, they can let you know if you have the right amount of freon, the operation of the orifice (plugging up with debris), the condensers ability to remove heat and the capability of the compressor.

Without looking at anything (Infrared scanning of components), a 0 PSIon the low side would tell me that your evaperator temperature is about -15 degrees and the a 100 PSI on the high side would tell me that your condensure temperature is about 87 degrees.

 

The guages are jumbping back and fourth on the Manifold guages. The hands on the dials are jumping around.

 

All auto A/C service starts with pressure gauge readings. In order to get the pressure gauge readings you require a set of manifold gauges that will connect to the high and low pressure sides of the A/C system.