ac compressor cutting out

[timd]

2002 XLT, 3.0L. Flex Fuel, Would a TPS cause an ac compressor to shut off & on? I know that at WOT, the computer will turn off the ac compressor to allow full power. But, I can be driving at a normal street speed 35-40 mph and the ac will not be cooling. If I hit a bump, the cooling comes back on....or it will eventually come back on on its own. Any suggestions?

[brcidd]

Your air gap between clutch plate and pulley face is probably worn too wide- it pulls in when bumped after it cycles off. To test this - next time it is "off" when you know it should be on- pull over, pop hood- take something like a wooden hammer handle and tap on front of compressor- if it engages then you know this is the issue.

To lessen the air gap, remove clutch plate screw or bolt (in front center) and wiggle clutch driver off splined shaft- being real careful to notice any and all shims behind the clutch hub. Then remove the thickest shim and throw it away. put clutch back on splines, put bolt back in- and be cool from now on. Air gap should now be .020" or less (the thickness of a business card).

Very, very common problem on vehicles with 110k miles or more....

[timd]

Thank you brcidd! I never thought of that. Most threads about TPS said that the engine was idling rough, sluggish, etc. My Ranger doesn't have those issues. I will try Key On, Engine off and see if I can turn the clutch plate at all. Thanks again!

[timd]

I was able to check the ac clutch when it stopped cooling. The clutch was not engaged!!! I tried wiggling wires, tapping on TPS and Hi & Lo side ac pressure switches. Nothing made the clutch engage. Shut off the engine and checked some more stuff. Cranked up again and the clutch engaged. There was a definite difference in the position of the clutch. I will try bypassing the ac compressor relay to see if still drops in & out. If it does, then maybe my clutch coil is intermittent. If it doesn't, something is telling the computer to turn off the ac compressor.

[brcidd]

Your issue is not electrical-- it is a too wide of an air gap-- to prove it, next time it is off when it is supposed to be on--get out, keep engine and a/c on- pop hood and tapon front of compressor with a long stick, or hammer handle or something just to bump clutch- such that it can jump across the air gap and engage. if it engages, then you now know what your issue is- and ahave confirmed your air gap is too wide-- now pop clutch off, be careful not to drop out shime from behind it-- take the thickest shim and throw it as far as you can, then put it all back together and test...

[timd]

brcidd
Sorry, I thought I already thanked you for your suggestion. Yes, the air gap was too wide. It was about 0.040". Removed clutch plate and removed the only shim and reinstalled clutch plate. (cleaned surfaces also). Air gap is now about 0.020". A/C is working great! Thanks again.

[brcidd]

Just think, if you would have taken it to a shop- they would have put a new compressor on- and it would have cooled fine....but you just saved about $800 by asking around and doing it yourself--good job! Isn't the internet wonderful?