Clutch seems to engage and release at it's own free will...

When the engine is running and the AC system is turned on, I get 12V at the clutch plug, but when I connect it back up, the clutch doesn't engage all the time.

Is the cltch bad or does it need adjustment??

A collegue mentionned that the system could be low on refrigerant. What I don't understand is if this was true, I would not be getting the 12V at the clutch. Or am I missing something??

How hard is it to replace the clutch? And what does it cost (ballpark)..

Thanks.

 

Year, make and model would help a lot.
When the clutch won't engage with the AC turned on, tap the face of the clutch with a screwdriver handle, broom stick or other suitable device. If it engages, the clutch gap is too wide and needs to be adjusted.

If it doesn't engage, you have another issue.
-Make sure you also have B- (ground) at the connector.
-Do the checks with a test light, not a volt meter. A meter can show proper voltage even if there is high resistance in the circuit. There can be 12v there with no load, but almost nothing with a load on the circuit.
-If you have voltage at the connector, it is not likely a refrigerant issue. There is enough pressure in the system to at least engage the clutch.
-Check the resistance of the clutch coil. It should be 2-4 ohms with no continuity to ground.

 

Sorry, I meant to give those details...

97 F-150 V6 (4.2) 2 wheel drive...

I'll check the the Resistance of the coil today. The AC ran OK for a while yesterday, so I couldn't try tapping the face of the clutch.

Here in Canada, the Dealer wants 137.31 plus taxes for a new clutch. Is that reasonable or can they be had cheeper. Just need to get through the summer.

Do you have any steps to adjusting the gap? Where do I check this gap?

Thank you..

 

OK, I think I got it going OK..

With the Engine off, but the ign ON and all the switches set for AC, I connected the Clutch harness and nothing happened. I could still rotate the clutch plate by hand. If I pressed on the plate with little pressure, it would engage (click) and I could not turn the plate as it is sitting up against the pully (which of course isn't turning). I removed the plate, cleaned up some loose debris, removed the one and only shim put it all back together and it workd right away. My concern with removing the shim was that it would be too close and run all the time, but it's not the case. It runs when needed and when the engine is running without the AC turned on, the plate is stationary, turn it on and alas, there she goes....

Just thought I would state my findings...

By the way, resistance in the coil is 3.4 Ohms... well within your range above....

Thanks

 

Good work!
Now, just take the center bolt out of the clutch plate and slide it off. Look for a shim or two in the splined hole in the clutch plate. Remove the thickest one (or the only one). Reinstall the plate and spin the pulley. If there is no rubbing between the pulley and the clutch, you are good to go. If it rube, you may need to obtain some shims to get the gap at .020" or less. It's not a precise measurement, just less than .020" without rubbing. If there is only one shim, removing it "usually" brings the gap in to spec.