Any A/c experts

Follow your lines from the A/C compressor. Usually the expansion valve will be very close to the evaporator which is usually integrated into the blower box housing with the heater core too. I am not sure on a Pete, but behind the glove box area is popular. If the low side is high, but the high side is normal chances are the expansion valve is stuck open.

 

Make sure your heater valves are closed before you take AC readings. this time of the year if the heater valve leaks past a little it will seem like the AC is not doing its job. expansion valve is most likley under the hood over the exhaust pipe on the fire wall. also check dust filter inside cab under dash on rt side

 

Newer Petes do not utilize the receiver-drier w/expansion-valve type A/C system. They've gone the way of GM with the orifice tube in the inlet port of the evaporator. Thus, you won't find a receiver-drier as is typically installed between the condenser outlet and an expansion valve inlet; but you will find an accumulator between the evaporator outlet and the compressor inlet/suction.

 

Sure it could. orifice metering is cheaper than traditional exp valve type. These are normally set in hundreds or thousands of an inch so a little speck of crap can cause a restriction. Some will ice up at restriction but not always. You need to measure the air temp entering the evap coil and discharging into cab. Some one else said to check heater valve. this is very good info. a little bit of heat can temper your a/c enough to make it not seem to be operating.

 

I would check the evap coil and make sure it is clean. It absorbs heat inside and if it is dirty you will lose a lot of capacity. Need to check your refrigerant charge also. If it is overcharged it will not cool properly. Too high a charge makes it blow out warmer and can ruin compressor. Too little won't cool or may cool until it ices up. Wash out the condensor coil as well. It gets rid of heat evap coil picks up in cab.