1993 Mazda B2200 AC

[itoyota]

My AC sometimes blow cold air and sometimes not. I check the AC switch and thermostat and both seem work. I take it to a shop and they work fine there and have enough freon. Now she just blow air nothing cold. At this point i don't know what to do.

Thanks

[bradrhale]

did you verify that the clutch was engaging?? if the system is full, also verify that both pressure switches are in working order.

[itoyota]

Yes the clutch engage and the system is full. I don't know how to check the pressure switches

[bradrhale]

unplug the low pressure switch. take a paper clip and insert it into both sides of the plug with the wires. if the clutch engages with the clip in the connector but not when it is plugged in, than you have a bad switch.
if your clutch is engaging and staying engaged, than it is not going to be a pressure switch problem. will the clutch stay engaged when the engine is running or does it click in and out??

[itoyota]

when you say low pressure switch is the AC switch? The clutch stay engage while the engine is running

[bradrhale]

if the clutch is staying engaged, then your problem is not going to be a pressure switch. since the system is running, then there should be no problem with the ac system. you might check to see if your coils are clogged with junk preventing air flow through the evaporator coil. that would be my last guess. really only other thing it could be.

[itoyota]

I take the truck to a local A/C shop. They said that my Expansion Valve is bad. The part cost $50.99, but they want to charge $361.00 for install the valve and put new copper retrofits. I still think that is too much so I didn't pay for the repair.

[bradrhale]

didnt know mazdas had expansion blocks. most vehicles have an oriface tube, but there are some that use blocks such as vans that have front and rear air. the blocks use threaded couplers and is easy to install. no sweating involved. that block could be the culprit. however, if the block was malfunctioning, you would not get an accurate reading on your pressure gauges to test for a full system. what new copper retrofits are they talking about??

[chankee]

Don't pay that much, you can have it lesser that that if you know what to do. Maybe the exhaust, accelerator and exactly the A/C needs to be cleaned and/or replaced. you can look a lot of mazda replacement parts anywhere near your place, from friends or online.

[itoyota]

I finished taken the truck to another shop. I buy the dryer and the expansion valve on advanced auto for $49.00. The system was vacuum, replaced the oil on the compressor, installed new oil rings, dryer and the expansion valve. He charge me $253.00. But I can't complain I have this truck since 2000 and she deserve it!

Thanks guys for your help!