Evaporator freezing up

[automile]

I have a 2011 Ranger that has had great ac till just a few weeks ago. Now the compressor doesnt cycle off and the evaporator seems to freeze up.if you turn it off for 10 min or so it goes back to blowing cold air till it freezes again. cold it be a bad low pressure switch? if so are the on a schrader valve or do I need to open the system up? thanks everyone!

 

[adsm08]

A low pressure switch that is shorted does sound likely. It would be best if you could get some gauges on it and see what the low side is doing.

 

[Uncle Gump]

I do believe most are on a schrader valve.

 

[RonD]

Yes, as odd as it sounds low levels of "freon" cause freeze up

AC works by compressing "freon" then allowing it to expand, the more and faster it expands the colder it gets, so when system gets low on "freon" it can expand more and faster

Low pressure switch should prevent that, but could be stuck or right at the edge of shut off