I got a problem with my AC, i turn it on and i hear and feel the engine change as if the AC was on but the air blows warm, I already recharged the system and it did have a leak in the valve so i replaced it, and added freon, i also jumped the clutch cycling switch and it also works, the clutch does not engage and everything is connected, any ideas?

 

If your compressor clutch will not engage it could be a faulty temp switch which is attached to the evaporator to cut the system off if the evaporator freezes. if you jump the wires and the clutch engages a new temp switch will fix it. If it doesn't then you need to check the compressor relay. The condenser fan relay is the same so you can just swap them to see if it fixes it. Your A/C switch is working and the ecu is working since you said the rpm changes.

 

okay, i swapped the relays and its still not cooling, you know which one of the two switches on the ac fan assembly the temp switch is? there's two of them one above the other on the side of the fan assembly.

 

What model year?

If the engine revs up it is wanting to engage the compressor, pressure and switches are OK-- so it could be the compressor clutch, relay, thermal protector (some years) or fuse (if fuse is bad, condenser fan won't run either).

It's very common for the clutch to wear so the gap between the plate and the pulley is too large for magnetic force to pull it in. Jump the compressor to the battery WITH THE ENGINE OFF and see if the plate pulls in. If it does not, press on the plate (ENGINE OFF) and see if that makes it snap in.

If it does you need to adjust the gap. That is done by taking the plate off and removing shim washers from behind it. It can be done with the system charged if you unbolt the compressor from the engine-- don't disconnect the lines-- lower it down and unscrew the shaft nut.

If the clutch does engage with power directly applied, but not when plugged in normally, check the relay next. The ECU supplies a ground to the relay coil after it revs up the engine. DO NOT BE TEMPTED TO JUMP THE COMPRESSOR WITH THE ENGINE ON. That is prone to cause an overpressure and blow a hose or the relief valve.

 

its a 2000, before i found the leak and i had added freon, i would be driving normally with the ac on and it would work fine but randomly turn off and on.. and i would feel the change in the engine as i drove, i found if i revved the engine a lil higher than normal, the ac would cool fine, but if the rpms went back down, i would feel the engine change and warm air again.. i dont know if that helps.

 

Cooling intermittently.. really sounds like a clutch gap issue.

 

Off the top of my head I can't remember which one it is. Simply trace the wire into the plastic housing for the evaporator. I'm assuming that you have already checked to make sure the fuse was good for the relay. Is the system charged properly? you should have a high side pressure about 2 to 2.5 times ambient temperature.

 

ahh okay, i think im gonna replace the whole compressor. thanks alot for the help guys!