We had some sensors changed some months ago because the AC would not blow cold, it was making a noise like something was hitting the fan under the hood and it just would not blow cold air. We thought it was the compressor but we were told it was some sensors, well yesterday it was 107 here in Houston and it did it again, can anyone help with what sensors i will need?

 

Welcome to the forum...
What year of vehicle and engine size?
I can think of no sensors other then the temp sensors at the front of the vehicle and maybe the pressure switch at the accumulator.
Only sound I can think of making a sound when the AC is on is the clutch engaging and dis-engaging.
I would consider taking it back to where you had the service done as it may still be under a warranty of some type...

 

What, if any, sensors did they replace when you had it in?

 

Sorry for my ignorance, 2002 Suburban Z71 5.3l, and I will take it back after the holiday weekend but we like driving our Burb over my twins Durango, we have room for our two sets of Twins in the Durango but a lot more in the Burb.

The noise was coming during acceleration but would go away at highway speeds and never affected the cooling at all, it has us baffled.

 

Could be that your airflow actuators (blend doors) aren't calibrated. This happens often if you disconnect power to the A/C. The reset procedure is easy though and works for automatic climate control. Not sure about manual though:

1) With the ignition in the off position, pull the HVAC/ECAS fuse from under the hood for a minimum of 10 seconds.
2) Plug HVAC/ECAS fuse back in
3) Turn ignition on and wait for 40 seconds for A/C system to calibrate.
4) Does it cool now?