A/C Trouble

[stadair]

Originally Posted by Cobra Jet

... If by jumping the switch the A/C kicks on (air is getting cold) and the compressor cycles over (clutch activates at normal intervals), then your problem is the A/C pressure switch.

Now - if when jumpering the A/C pressure switch connector your A/C compressor cycles sporadically, or I should say, it keeps turning on then off rather quickly, then the A/C system is low on freon. You would then have to check for leaks, because adding new freon would be waste if you can't find the source of the leak.

The A/C pressure switch is the most common point of failure within an A/C system, especially on the Mustang 5.0's (also prior F-Series and Broncos). It's a cheap part than can be easily diagnosed. Sometimes they can be bad right out of the box too.

Best of luck!

Phil - I did as you suggested. I got the compressor to turn on. And it ran continuously. It never did cycle on/off, but I only ran it for about two minutes though. The air did not get cold. Nor did the A/C line on top of the pump get cold. Condensation usually accumulates there, here in the humid air we get in Michigan.

Maybe I have a bad pressure switch and leak at the pressure switch?