Ac Issues, Very Odd Problem, Never Seen Anything Like It

[YukonXL04]

Okay, hi all, I am new here, I have 2000 GMC Sierra 2500 4x4 with a 6.0L and 4L80, and I am having AC issues.

First off it works sort of, when the engine is cold the AC will work great and ice cold, but if I change it from lvl4 to lvl 2 it will quit working in a few miles, but if I leave it on 4 my whole way home it will work the whole way, but if I shut the engine off, it won't come back on... I have checked the freon lvls and they are good, and tried replacing the sensor on the aluminum can thing, sorry don't remember the name. And no change, just trying to figure it out...

 

Thanks a lot!!

[GMcarnut]

Okay, hi all, I am new here, I have 2000 GMC Sierra 2500 4x4 with a 6.0L and 4L80, and I am having AC issues.

First off it works sort of, when the engine is cold the AC will work great and ice cold, but if I change it from lvl4 to lvl 2 it will quit working in a few miles, but if I leave it on 4 my whole way home it will work the whole way, but if I shut the engine off, it won't come back on... I have checked the freon lvls and they are good, and tried replacing the sensor on the aluminum can thing, sorry don't remember the name. And no change, just trying to figure it out...

 

Thanks a lot!!

 

4x4 6.0,

 

There could be a problem with any one of the five major components for your A/C system. Have you checked out the condition of the Evaporator? (Part 89018270) What about the condenser? Compressor or Expansion Valve? These are some of the major components of an automotive A/C system so I would have a mechanic inspect these respective parts to determine whether or not they may be the catalyst of your A/C issues. Good luck!

[snake428]

Check the A/C compressor air gap anything over .030 and it needs to be tighten a very common problem on those trucks.