A/C clutch

[Doug Waschenko]

Can anyone save me some time on an A/C problem?
My clutch is shutting down after running about an hour.
The system is fully charged. I don't see it freezing up.
Anybody with a similar problem? Is this clutch failure or pressure switch?

 

[K-Dawg]

Do a search and you will find very much information on this common problem.
Start off by making sure the clutch coil is getting power at it's connector. If it is, measure the clutch air gap, which should be less than .035" (I think). If it's too large, read the procedure on SHOTimes for removing the shims.
Most likely this is your problem, but there are many reasons for a compressor clutch to not engage.

 

[rangerj]

Doug,

With your engine and A/C system dead cold, unplug the low pressure switch connection and jumper the connection. Then put the key in the KOEO position and the A/C in the on position. The clutch coil should become a strong electromagnet.

It should because the coil is cold. Next, take a ride with the A/C on (the low pressure connection has been put back on the switch). When the A/C quits working because the clutch will not engage pull over and park someplace safe. Then do the test again before anything cools down.

If the coil fails to become a magnet, the coil is defective. You may have a winding in the coil that is broken but only pulls apart when the coil is hot and expanded, thus causing the coil to fail.

If that ain't it get back to us and we'll try something else! rangerj

 

[Doug Waschenko]

So far the shim trick is working. My feeler gauge reading was over .050.
When I pulled the clutch cover off I only had one shim in it that measeured .042.
I had to make a shim to bring it down into specs.
If it doesn't keep, I'll try the coil test Ranger.
Thanks for the advice. It saved me a lot of needless diagnostics.