97 AC issue - 5 min cold 2 min hot (1 Viewer)

[South Texas 97]

Was having an issue with my AC. It would blow cold just fine for 5 minutes, and then blow hot for 2 minutes and then cold again. Yes, I timed it, and it was pretty consistent. i have no AC test gear so took it to my local experts. Their diagnosis was the fan clutch, which was original with 330k miles. Replaced the fan clutch, and we have cold air all the time now. This is quite useful in South Texa.

 

[DSRTRDR]

 

[Kernal]

Was this occuring in slow traffic, at highway speed, idling and not moving or??
Is the Thermostat the original also?

The AC turns off when the coolant temp gets too hot (I forget the number, >220F something).

 

[enox]

The AC turns off when the coolant temp gets too hot (I forget the number, >220F something).

A/C knocks out at 226 and will not come back on until it drops to 217

 

[South Texas 97]

Thanks for the feedback folks, now I understand why it was cutting out.
Thermostat was new OEM, I had previously gone through the coolant system, fixed the radiator, replaced hoses, changed water pump and thermostat, and checked and cleaned the oil cooler embedded in the block under the exhaust.
It was happening at all speeds, but most noticeable at highway speed.

 

[flintknapper]

A/C knocks out at 226 and will not come back on until it drops to 217

Correct and good info for folks to have. Many a person not familiar with the system have become perplexed when this happens *temp cut out switch disables A/C*.

It can be frustrating to diagnose and has led more than one person down a deep, dark, rabbit hole.