fan speed

[chauncey0337]

Hey all. I usually hang out in the 2000-2006 section but I have a friend who has a 1999 obs yukon slt and he's got a problem. So, I figured I'd come here. He's telling me the heater fan stays on hi all the time even when the switch is in the off position. Is it just the fan speed switch needing replacement or is it more complicated than that? Thanks.

 

[drowndindreams]

tell him to turn off the recirculate button. our tahoes and yukons are infamous for blowing air out when we don't want them to. luckily you can still adjust the temperature

 

[chauncey0337]

tell him to turn off the recirculate button. our tahoes and yukons are infamous for blowing air out when we don't want them to. luckily you can still adjust the temperature

The fan stays on high (power, speed) no matter what.

 

[drowndindreams]

could be that there are bare wires behind the HVAC. or, less likely, the buttons are broken. pull them off to see if the plastic cylinder is still intact

 

[SunlitComet]

that would have to be the fan switch internals if it runs on high only when ignition is on. If it runs on high with key out the power relay is jammed/shorted.

 

[chauncey0337]

could be that there are bare wires behind the HVAC. or, less likely, the buttons are broken. pull them off to see if the plastic cylinder is still intact

OK, we'll take it apart and check. Thanks.

that would have to be the fan switch internals if it runs on high only when ignition is on. If it runs on high with key out the power relay is jammed/shorted.

Yes, runs on high when ignition is on. probably end up replacing the switch. Thanks for the input guys.