AC knob only works on full power/ strange fuel issue today-2004 Colorado

[tom ruth]

Hi Guys,
I have a 2004 Colorado (112k) and the ac only works on full power (setting #4). If I remove the knob and put it back, I sometimes get air on the other settings. I live in south Florida, so it is an issue this time of year. Running it on 4 is loud and eats gas.

Issue #2: Today I drove my car home and it would not start, but it was turning over. I assumed then that it was fuel related and not electrical.Later in the day, it started right up, so a knowledgeable friend suggested a fuel pump relay. Any thoughts?

Thanks in advance,

Tom in Florida, a proud Pittsburgh Pirate Fan

[TexasTechRaider]

Have you checked the resistors? Those often go out and I have seen others have problems all the time. It could also be the connection in general or it could be the relay. It's most likely the resistor and it goes out on lower setting more often since those are the settings most used, it's often refereed to as an resistor pack and they are relatively cheap as well. Welcome to the forum as well!