ac frezzing up

Freeze switch maybe?

 

Orfice tube/expansion valve
improper charge
Air flow problem
Thermostatic temp control switch
Blend door operation
restriction from debris in system

 

Dirty/Clogged evaperator. Which falls into the above Air flow problem.

 

It doesn't matter what is wrong the a/c, if the evaporator is getting too cold the freeze switch should trip and shut off the system. Since the evap is freezing up that switch isn't working. That would be the next direction I would look. What does a 06 Pete use for evap temp sensing? When you changed the evaporator was there a long skinny tube probe pushed into it?

 

Tx valve, will be in the line between the condenser and the evaporator.

 

This truck should use pressure switch to cycle the compressor. This switch is gray in color and in middle of pipe right against firewall. It is either bypassed or shorted. It should #### commpressor off at around 23psi and back on at around 40 psi lowside.

 

Check to the compressor relay had a 04 pete freezing up the relay was shout and compressor would not shut off

 

TruckMechanic you are right never have had it happen on ac but clearance lamp relay rainwater causeed this though it leaked in through clearance lamp the relay was all green and swolen.