Recharged my A/C 2day on my '91 f150 XLT 5.8, worked for about 2 mins. and the compressor stopped working, it still rotates but doesn't engage. changed out A/C switch by the dryer, still nothing. Any ideas? Thanx ahead of time!

 

Jump the plug out on the clutch cycle switch to see if the clutch will pull in.
If it does you have a leak or not enough freon in the system.

 

There's a low pressure switch that shuts off the compressor if the suction side is too low (not enough refrigerant). There should also be a high pressure switch that shuts off the compressor if the output is too high (blockage). At the very least you need a set of guages to see what's going on.

 

Use a multimeter. Select ohms setting. To check if meter is working before doing any testing. Touch meter test leads together and see meter dial or dig. Read out changes. If they do you are ready to check switches to see if voltage will pass thru them. Unplug wiring from switches and and put meter lead on switch wiring connection. If switches are able to let power thru then meter dial will act as it did when leads were put together for meter test.
If no change then switch is open and no power will go thru switch.
If high pressure switch is open.You have a high pressure situation. A set of refrigeration gauges will tell you that. Causes.Air in system. Not enough air thru condenser. Dirty condense. Too much freon in system
Low pressure switch open. Not enough freon in system.
One caution. Air getting into any a/c or refrigeration system is bad. R-134a systems can be ruined by poor service practces.
I just brought back to life an old r-12 system on an 89 f-150. I had a small R-12 stash.
Low pressure switch is on accumulator or anywhere on suction line. Cold line. High pressure on line anywhere from compressor discharge line to inlet to evaporator coil.

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