AC clutch

[Enigma346]

From what vehicles would an AC clutch be able put on my AC compressor? Does it have to be the same size motor?

 

[stamp11127]

What matters is the shaft size, pulley size and number of grooves. The compressor model is used on multiple vehicles & brands. Look at the Expeditions and Ford trucks of you are hitting the junk yards.

 

[johnboneske]

Whats it doing/not doing? Why are you replacing the clutch?If you have the issue of the AC running for awhile(say 20 to 40 minutes) and then it shuts off-or disengages the clutch from the compressor once it heats up... Loosen the center bolt, and pull the clutch out/off. You will see two washers behind the clutch, remove the thinnest one, which is about .040", and put it back together. Problem solved...I have done it to MANY cars/trucks/SUV's and not had to replace a clutch.

 

[Enigma346]

It's not turning on at all. The clutch/compressor that is. We jumped the low pressure switch, harness side and it didn't kick in. Tested the harness with a test light and it is getting power. Unplugged the compressor and ran 12v directly to it via a wire directly from the battery to it as if we were going a bench test of it. The clutch didn't even click or anything to show it was locking/grabbing. Of course we did that test with the engine off. Just to see if the clutch itself was engaging in the first place.

Also, after jumping the low pressure switch harness, should we have had power to the harness in which plugs into the compressor? Or does it go somewhere else along the way and then gets the okay to send power down?

 

[stamp11127]

A resistance measurement with a meter will tell you if the coil in the clutch is bad. How many wires are in the plug at the compressor?

 

[Enigma346]

2 wires on a harness.

 

[Big Brian]

it could still be what John is suggesting

while the engine is running and the AC is on try lightly tapping on the clutch face with a hammer or something similar, if it engages then you have too much clearance between the friction surfaces of the clutch discs

very common

 

[Enigma346]

it could still be what John is suggesting

while the engine is running and the AC is on try lightly tapping on the clutch face with a hammer or something similar, if it engages then you have too much clearance between the friction surfaces of the clutch discs

very common

Will give this a go. Thanks

 

[Enigma346]

Sorry for the double post. But I wanted to double check. This is the low pressure switch right? I'm pointing at what I think it is. I found a diagram online and tried to follow it.

 

[Enigma346]

Sorry for the double post. But I wanted to double check. This is the low pressure switch right? I'm pointing at what I think it is. I found a diagram online and tried to follow it. View attachment 24932

2003 Ford Expedition XLT 4.6L 4x4

 

[stamp11127]

• Check for battery voltage at the compressor connector and work your way back towards the battery following the diagram if voltage isn't present. Use chassis ground for the com/black lead on the meter.
• If power is present at the connector check the black wire on the plug for continuity to ground. If the meter reads OL or infinite that part of the circuit is "open".

 

[Big Brian]

If you use the chassis for ground make sure that the connection for your meter to ground is good.

Touch the positive lead of the meter to B+ to make sure otherwise you may be chasing your tail using a bad ground for the meter

 

[johnboneske]

No, the low pressure switch is on the accumulator next to the firewall. If you bypass it and it still doesnt kick in, 9 times out of 10 its the gap in the clutch which is the issue.

 

[Enigma346]

No, the low pressure switch is on the accumulator next to the firewall. If you bypass it and it still doesnt kick in, 9 times out of 10 its the gap in the clutch which is the issue.

No that, that is not the low pressure switch? It is right under those 3 or 4 plugs/harnesses?

 

[johnboneske]

I was wrong... On mine, its real close to the radiator and the high side service port. Close to the washer fluid tank.

 

[Enigma346]

If you're talking about the switch basically in the middle of your picture, isn't that the high pressure switch? I have one there as well. Looks like the high pressure side. Smaller diameter ac line.

 

[johnboneske]

Well, that's the clutch cut off switch. Unplug it and see what happens...lol

 

[Big Brian]

maybe you are low (or out) on charge. Did you put gauges on it?

 

[johnboneske]

That's a good question. What are your pressures at? You should be around 45psi @75° on the low side.

 

[Big Brian]

well if the compressor is not spinning he wont have that

rule of thumb is static pressure (hi and lo side) should be about ambient temp