Auto Air Conditioning & Heater Repair: Blazer Compressor question, chevy blazer, vacuum pump

Question
I have a 1999 chevy Blazer with a 4.3 v6.

Recently the air stopped blowing cold. I tried using r134a into the inlet (low side) with the air running on high. The thing i noticed however is that the compressor keeps clicking. Seemingly on and off.

Is this ok. Is this an indicator of a more serious problem?

Thanks
Daniel

Answer
You can have one of the following problems:

1. Not enough freon in the system will cause the compressor to cycle ON and OFF..

2. atmospheric air has gotten into the system which will cause the compressor to cycle ON and OFF.

3. The system has to much freon and or air in it which will cause the compressor to cycle ON and OFF.

4. The PRESSURE CYCLING switch is defective which will cause the compressor to cycle ON and OFF.

This is why you need a set of A/C gages and a vacuum pump to install on the system to see what the LOW and HIGH side pressures are at BEFORE you can determine which of the above is your problem.

Without a set of gages you are only GUESSING at what the cause IS and how to correct it.



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