My A/C will work fine on every setting except for 5, I don't know alot but does anybody know what the problem is? And also when my truck is off even on 4 and on all the way cold it will blow hot air but when I turn it on it starts blowing out cold air immediately, I have know idea what these mean even though there not major problems I would still like them fixed. So any help is appreciated.

You probably need a new blower motor resistor, that's usually the problem when just one or a couple of the speeds quit working.

As far as your second problem, I don't understand why you would need it to blow cold air while the truck is not running. But it never will, the compressor is driven by the engine, so if the engine is not running the compressor does nothing so that's why you are only getting warm air.

Ok thanks for the info but for your understanding, I have to pick up my girlfriend from volleyball practice so I don't sit there with the truck running forever i just turn it off, turn the key, and let the a/c run and I didn't know why it wouldn't blow cold air but now that you explain it...it seems like common sense and I kinda had an idea that's what it was in the first place.