I got a 2004 Ford ranger with the 3.0, it’s full of Freon and there’s no condensation on the lines so I’m assuming no leaks. However, even on Max cold a/c it blows hot air. The compressor seems to be running all the time, even when the a/c is on the off position. Which I find odd but I’m not sure why. Any help? Thanks.

 

You say its full of freon, have you had the guages on the high and low sides... what was your readings..... the high side line should be cold to the touch..... magnet hub in the front of the compressor what happens when you unplug the compressor connector, if the compressor is running all the time..

 

no line is cold to the touch in there. I have to get my readings tomorrow. And I say it’s full of Freon because I tried to put a can in it thinking it was just low and it wouldn’t take any.

 

Welcome to the forum

When was the last time it worked?

Turn control in cab to OFF not just the AC
Compressor should run in all positions except OFF, it is used to dry the air in the cab.

There are two pressure switches on the "Freon" lines, find them, disconnect the 2 wire connector on each and look inside to make sure no one install a "jumper" to bypass the pressure switch

Your filter/drier or expansion valve may be clogged, BUT....................high and/or low pressure switches should cause compressor to cycle on and off quickly if that's the case


And just FYI, on all cars/trucks, MAX AC just closes the Fresh Air Vent, so you recirculate already cooled air inside vs cooling the hotter air coming in from the outside
AC only has two selections, ON or OFF

Oh on some, like the Rangers, MAX AC also stops coolant flow thru heater core

 

I changed it to a new compressor, it worked for a while, nice and cold, but now it stopped working. Probably around a month or two ago. I’m not sure why. I’ll check those things tomorrow and get back to you.

 

Did you add oil to the compressor?

Did you change the drier and orifice tube with compressor, you have to do that when system is exposed to air

If it worked then pressure switches are fine

 

I added oil but I didn’t change the Drier and Orifice tube, it was blowing cold air for a little bit without those changed though. Also I disconnected the wires from the compressor and it’s still on, that’s weird.

 

Sounds like the compressor clutch is frozen .. you can remove the 10mm bolt and pull the hub off............or warranty on the compressor take it back.......... every time you replace the compressor you have to replace the drier etc