Hey there,

I have had my truck for a few years now, bought it used obviously. And the AC has never worked. It looks as if everything is there, the blower works, but it isn't cold at all.

I had a friend that knows " a little " more about AC's and what not to try to recharge it, and he said that it was full. I do not know what to listen for as far as the compressor or anything like that. I was hoping someone would be able to steer me in the right direction as far as what to check / replace first.

Any help with this would be greatly appreciated. Thanks!!

 

As you are standing in front of the truck, compressor is on the top right. There is an outer pulley, that the belt rides on, and an inner pulley, that is part of the clutch. When the clutch is NOT engaged, the center portion is stationary, when the clutch engages, everything turns. Start the truck, turn on the a/c, and watch the compressor. Is the clutch engaging?

 

No, I watched it for 5-10 minutes and it never came on. I do remember seeing it come on before, not lately though. It would basically come on for a couple seconds and then go back off. I would hear it every now and then click on and off when I was sitting at a light or stop sign too.

I have checked all the clutch fuses and switched the relay with a known working one, and still nothing.

 

if its full id try by passing the high and low pressure switches and see if that makes it turn on. if that doesnt make it turn on then and it is for sure full then hate to say it but your compressor is bad. when you change it you might as well do it the right way and change the drier orifice tube and compressor that way you wont have any problems later and have to do it again. make sure you flush the lines too

 

Ok, I am going to pick up a can with guages and try it myself just to make absolutely sure. If it is full, then my kids may just have to go without the AC for awhile longer..

 

So the system is definitely full, compressor is still not coming on. Nothing happens when I jump the switches.

Is there any other reasons the clutch would be competely seized up?

Assuming I have to replace the compressor, does anyone know a ball park figure of how much I'm looking at spending, and is it something I can do myself?

 

Can you turn the center portion of the pulley by hand?

Does the A/C relay click when you turn on the A/C?

Are you getting power to the compressor connector?

Have you tried swapping the A/C relay with the horn relay?

 

The center pulley does turn by hand, I switched the relays last night, but to completely honest, I couldn't tell you if my horn even worked. I haven't driven my truck all that much. As for the relay, I wouldn't have been able to hear it from inside the truck, I will have my wife switch it back and forth for me here soon.

And what would the easiest way to check for power be? I'm not familiar with AC units " at all " .

 

There is a two pin connector that goes to the compressor clutch, unplug it. With the A/C on, (engine running...) you should see 12 volts on one of the pins. (dark blue with black trace.) The other should be a ground. All you really need is a test light, but, a volt meter would be better......

First, check from the DB/BK wire to battery ground, should have 12 volts. Next, check across the pins, should still see 12 volts. Let me know what ya find.

 

So I switched out another relay, they all make the horn work. The last one I switched made the compressor come on in 1 second intervals and 5 seconds off. So I hooked the can back up and pumped some more 134 in. The crank spin longer and longer the more I pumped in, and I finally felt some cold air out of the vents.

The crank stopped spinning completely, it's blowing hot again. And it's measuring about 110 psi with the compressor not running.