EverydayDiesel

Sometimes when I get in my truck and turn the A/C on max or outside air it blows hot. Then randomly it starts blowing cold and other times it continues to blow hot (same as the outside air) the whole time.

When it does decide to work, it blows ICE COLD just like it did last year (ive been using the heater since then)


I dont know alot about A/Cs so whats the first thing I should check?

Busboy

Check the blend door posn. On the pax side down by the hump is the blend door actuator, move the **** from hot to cold and note the posn of the actuator in each posn. Then next time it blows hot when you have cold selected see where the blend door is posnd. If its not in the correct posn then its probably the actuator or its broken off the door arm.

If all this is working correctly then see if the compressor is actually putting out cold freon to the evaporator. With the eng running just feel the large line by the firewall, it should be cold, if not then your AC is not producing. BUT as you say it works sometimes, then it could be a broken wire butting end to end. With the compressor not engaged but AC selected feel around the wires and see if the compressor engages.

If you can't get it to engage then short across the hi and low sensors one at a time to see if it will engage. It could be a sw sticking.

EverydayDiesel

I looked under the truck and it looks like the A/C pump is not turning.. this would be why its not cold but how do I fix it?

MAX340

Not trying to be smart, but take it to a professional and have him deal with it. You cannot open the system without evacuating the refrigerant. Its likely you don't have the tool to do that. You may be able to convince them to take the R*** out, and let you replace the parts. But again, I recommend just allowing them to take care of it if you don't have the tools.

The reason the compressor isn't turning, assuming you have the AC turned on, is because of a low pressure cut out. This suggests that you have a leak. It is very likely that the leak is in the evaporator under the dash. This too can be done at home, if you feel you have the skills.

In refilling the system, it MUST be under a solid vacuum for better than an hour to evaporate any moisture in the system. Plus, this will prove its been sealed by the repairs.