98 Explorer a/c switch?

[bbkimports]

I just bought a 98 Explorer and am happy so far; however, I live in Florida and need a/c. Previous owner said a/c needs high-low pressure switch only. Blows cold air 5 minutes then warm moist air. Is the switch bad? Also, do I need to evacuate a/c lines before changing? Your answer will let me know if I need to take to shop or if I can do at home. Thank you for the help and I really like this site.

 

[Mike65]

Welcome to EF.

 

[SoHK_alumni]

Both the high and low pressure switches can be changed without recovering the refrigerant.

The switches have a small tip on them that opens the a valve in the stem just as they tighten down. A small release of refrigerant is expected when changing the switches, just keep turning the switch once you hear the "hiss".

But, I'm concerned about your symptom and really think a better bit of diagnostics are in order. A set of gauges on the system and noting what the pressures are doing both while cooling and once the symptom occurs would greatly help to show what's going on.

To guess, I think you've got a blockage at the orifice tube but without guages and pressure readings, it's very difficult to say for sure.

 

[bbkimports]

Thank you for your help. The previous owner told me a/c shop diagnosed it. I guess I will have to go to the shop on this one.