Ice cold/then hot...1 hr later after sitting -cold again - My AC did something weird today, and i came on here and searched this forum but i am stumped. Truck ...

My AC did something weird today, and i came on here and searched this forum but i am stumped.
Truck is a 2005 GMC Sierra SLT, 5.3L. , never had an issue before with the AC, it is ice cold!
On the way home from a camping trip today, about 10 minutes into the 30 minute drive home the ice cold air suddenly went to to hot air, even though the temp was set at 15 degrees with the recirc on. i tried different vent settings, different fan speeds, recirc on and off and all i could get was hot air, so i shut it all off, and tried again in my yard when i got home....same thing.
I unloaded all our camping gear, came on here an been reading for about an hour but no luck finding a similar issue.
I went out and looked under the hood, belt is on, everything looks as it should, start truck and now i have ice cold air again.

Any ideas what would have caused this, it's going to be 30 degrees celcius and higher with the humidity this week, so AC is a must with my two small kids.

Thanks.

Checked freon?

No i haven't, how do i do that?

With a gauge at the service port, they make a gauge kit that you can use to add freon also. If low on freon the compressor will turn itself off...

Thanks

It sounds like your compressor is beginning to go bad,Mine started doing that a while back. I tried checking and adding freon, it did not work I finally took it to the shop and they rebuilt the compressor for me, they said it was beginning to go bad

That is possible also, the compressor has a cutout on it when low on freon. Freon doubles as a lube in there... So it cuts off when low... Its cheaper to check the levels first

This is true, follow up with what Mach said first. It's always better to go the cheaP route first and that fix your problem, rather than spend the money out right. Check and see if it's your freon and thats just a 15 dollar bottle of freon at Walmart, if not check into the compressor issue.

Thanks, will check that.

The AC was working fine, then last night on the way home i started to see some smoke coming from under the engine hood when i stopped at a set of lights...checked gauges thinking it might have been overheating but it was fine, jumped out and popped the hood, didn't see anything or where it was coming from. Drove to my brother-in-laws who is a mech and we seen that the clutch/pump pulley was wobbling, so we cut the belt off.

He said it looks like i'm going to have to get a new AC belt,AC belt tensioner, and a pump- but he was wondering if you can buy a clutch for it seperate.

Any input?