AC evaporator freezing

[HoosierJeeper]

So apparently my AC evaporator is freezing up. Gradually chokes the airflow (takes about 2 hours of continuous driving), thaws out overnight and works fine. What should I check? Looked on an F150 forum and they mentioned the drain and the low pressure switch.

Thanks!

 

[tjkj2002]

You mean evaporator?


If the condenser is freezing you have some major issues or a real freak KJ.




Most common cause for the evaporator to freeze is a low charge in the system.

 

[HoosierJeeper]

I mean evaporator...thanks.
The AC blows cold still. I was reading this thread, exact same issue I have.
A/C seems to "Freeze Up" during 1-2 hours of use ... Anyone fix this before???

 

[tjkj2002]

I mean evaporator...thanks.
The AC blows cold still. I was reading this thread, exact same issue I have.
A/C seems to "Freeze Up" during 1-2 hours of use ... Anyone fix this before???

99.9% chance your low on R134A,just because it blows cold does not mean the system is properly charged.

 

[HoosierJeeper]

Would it be worth trying to replace that low pressure switch? And can I top it off myself?

 

[adamkrz]

The two possible problems are either low refrigerant or lack of air flow through the coil..

 

[HoosierJeeper]

Got it booked today for a vac and recharge.

 

[uss2defiant]

I think you'll have to evacuate the system before you can remove and install a new low side sensor.