so when the truck is on max ac i no longer get cold air, but on A/C it still works

and sometimes it wont switch out of defrost to the other settings and will just blow the air out the dash

fuse?
switching mechansim?

figured id ask before i started looking at diagrams

 

figured id bump this

 

Sounds like you may have a vacuum leak. I would check the lil black ball with the hoses running to it on the passenger side under the hood.

 

X2^^

 

Also pull your radio out and make sure the soft pliable vacuum tubes that plug into the HVAC are not kinked or squashed back in there.

 

lol thats probably the problem, put in a new deck not too long ago

 

Looks like someone needs a smack in the back of the head! lol jk

 

Good call