A/C compressor not turning on?
 

When I bought my truck the previous owner said that the A/C needed to be recharged but worked.

I went to turn it on the other day and the compressor isn't even turning on at all...

Any ideas? I checked fuses and all the plugs are seated...

Did you charge it? If not it's probably low. Pull the low refrigerant sensor off the drier and make a jumper for the plug. If the compressor cycles, you are probably low on frig'nt. If you charged it, it could be over charged.

I know mine started smoking when turned on. If you checked all the fuses and the wiring going to it then like JAFO1 mentioned check the above.

Like stated above, probably open on the low pressure switch. Jump it out see if compressor engages

When the charge is just low you will normaly see the clutch cycle off & on, unless it is pretty much dead empty. jumping the switch is a good quick test off the electrical system. if the clutch kicks on, the switch is bad or system is empty. if nothing kicks on, it's time to get electrical. if you find the system is empty, I would suggest vacuuming the system out unless you are just checking for leaks. just pumping freon in will limit the preformance.

Where is the switch I need to jump? I havn't worked on A/C EVER! I havn't done anything to it since I bought it and the clutch doesn't turn on at all...

the switch on the accumulator r/s of engine bay.

When your A/C is low its because it has leaked down. (thank you Mr. obvious :)). You will need to fix it. There are no short cuts.

Best wishes!

B

is there a way to check if the compressor is locked? Can you turn it?

you should be able to move the front of the clutch (flat plate in front of pulley ) by hand at the least or with a wrench at the most. if it won't turn at all it may mean a locked up compressor.

One more thing to think about before you call it low on coolant. The connector on top of the a/c compressor at the rear. It's a round 2 pin connector. That is a high fail part. Turn the a/c on max, high fan. Go out and wiggle the crap out of that connector. I bet your compressor will kick on.

If it does, the connection just needs to be cleaned and tightened up. You could take a chance and crimp the female connectors a tad, and hope for the best, you could replace the connector.

I just took the red lock out of the face of the connector, took a few 3/4 inch long strands of wire, bent them in a U shape, and put them in the female end hanging half in and out of the connector. Then reinstall the lock and it will hold the copper strands in place. That one strand of copper will make all the difference in the world, and you shouldn't have any more connection problem. Hope that helps.

Also if the compressor comes on while the low pressure switch is jumpered, don't leave the jumper wire in. It is protecting the compressor because you are low on Freon. No problem to use the jumper for troubleshooting purposes though.

Thanks for the help guys... It's been raining so I havn't been able to work on it yet.

i dont mean to hijack your thread but i used this one to diagnose my own ac system that worked last summer but come spring it wasn't working, i jumped the low preasure sensor ac compressor kicked on so i bought some r134a and charged it to 45 psi now the ac works but it doen't seem as cold as it should be. if i bump the idle up to 1000-1500 the preasure drops down lower, my question is what psi should our systems be charged to?

It goes by weight to determine the charge. Theres a sticker under the hood that says the refrigerant (r134a) and then it will say the weight.
I don't know the weight off hand