Ac only blows cold when 95 degrees or below??

[jimeneztrans84]

On my 2011 kw t660 the ac only seems to blow cold when 95 degrees or lower. When I hit az or NV with 100 plus the ac is not near as cold. Even idling with cruise control on at 900rpm doesnt seem to get cold enough. When I'm in California its blowing cold. Is this normal or something is needing replacement?

[snailexpress]

Check recirculation/ventilation knob. In AZ you definitely want to use recirculation mode as outside air is really hot.
If AC is not efficient on recirculation mode the door and actuator motor place to check.

[Waterloo]

Under the hood, if you have a shut off valve for the heater core, turn it off or close it. More than likely that is your issue. You will find that valve on the passenger side of the motor, it will look like a water spigot valve or lever shut off valve.

[jimeneztrans84]

Check the valves and they were off. Also my clutch isn't engaging. Maybe my ac compressor is on its way.....

[Waterloo]

Is the engine fan engaging properly? Like when taking off from a light, with the AC on, the engine fan should kick on until you reach say 45 mph. May just be the high pressure switch is bad, or the wiring to it is broken, which has happened to me twice due to the way everything is mounted in my truck. If the engine fan is not engaging, pull the wire loom away from the high pressure switch harness, and inspect the wire. The high pressure switch should be on the top line coming from the condenser at the radiator. You do not have to drain the R134a to change that sensor.

And check the fuses, in fact, I would change the AC fuse, even if it is not blown. They get tarnished in time and stop working. A cheap fix.

[jimeneztrans84]

My engine fan is working. The ac clutch isn't engaging. The last time my pressure switch went out the fan wouldn't shut off. It's been like 5 or 6 years since I switched out ac compressor....

[Waterloo]

More than likely the compressor, or it is low on R134a...

[jimeneztrans84]

I will check the ohms on clutch. I think it should be over 3

[Chamberpains]

I usually just run straight wires from the alternator posts to the compressor clutch to see if its functional. 2' of wire, 2 alligator clips and 2 probe pins and you can check the Ac clutch operation in under a minute. If you drop the belt off of it you can spin things by hand and listen for bad bearings and compressors with broken internals.