Hey all.
Vehicle:1995 Chevy Blazer 4.3L 4 door 4X4

I have a problem with the air condition system.

Here are several things it does:

When i first start the car the a/c will blow cold/cool and then after a few minutes. Around 5 it will begin blowing in hot air. Then when i come to a stop light or an extended stop after hitting the brake the ac will blow cold again but this is not always a guarrantee.
Also sometimes it will stop blowing cold air when i accelerate. I know the compressor is designed to shut off at high rpms so it wold not get damaged.
I also checked the a/c vacuum reservoir and applied new vacuum hoses.
The system has been recharged this season and when i put a gauge to it it reads within specs.

Very rarely the ac will blow cold continously for about 15 minutes. I think thats happenned twice this summer.

Oh and one other thing on much cooler days the ac is able to blow cooler air for a bit longer.
Im very mechanically savvy with everything except a/c systems. never had problems with any of my cars except this one. Please help.

 

Tap on the clutch when it's not engaged but should be on and get back to me

 

it only happens when driving.the clutch actually engages when it sits. i will try to park it and leave it running and do what you said today.

 

I'll be watching this thread- I have a 95 Jimmy 4 door 2wd and I'm having a very similar problem with my AC.

 

Okay so the compressor does turn off from time to time. Now there is also a roar coming from the engine. Im thinking that the fan clutch is going out. Could this be a cause by any chance?
Anyways when i hit the compressor with a hammer it comes back on. should i replace it?

 

that could also be your pressure cycling switch too. next time its blowing warm arm, see if the compressor is off, then tap on the pressure cycling switch thats bolted near the dryer and see if the compressor goes on. if it does, then you need a new switch. which is cheaper and easier to replace than replacing the compressor especially that the compressor works and holds the freon.........

 

Bring it up from the dead! I finally took my Jimmy down to a local mechanic today due to the same symptoms the OP was describing. With mine it was because the air gap in the compressor clutch was not set properly. Now she works like new! Hope that helps somebody out!