Heater issue with my 03 Yukon XL

[Audball]

So I have an ongoing issue with my HVAC system. When I turn on my heat on it blows cold air unless I set it to MAX (90 degrees). Happens on both sides of the car. If I turn it from 90 to 89 it goes cold. I saw a recommendation on here that it might be the blower motor resistor that was the problem, so I replaced that. Had no effect on the problem. I recentyly replaced the HVAC control, so I know it's not that... Any help would be appreciated!!

 

[Scottydoggs]

sounds like a bad blend door actuator to me. ever hear a clicking sound from the dash? they glitch out when they go bad, or the gears strip out some times.

 

[OR VietVet]

Welcome to your 2nd post on the forum.

Yea, the blower motor had nothing to do with the heat settings. All it does is blow and the amount is controlled by the resistor. Does sound like an actuator. This time of year, they get a work out all across the country as it gets colder. Hell, here in the PNW, I hardly ever turn on the a/c in summer. Windows down and very comfortable. Unless the ladies in our lives don't want their hair to get messed up. I mean.....C'mon man!

 

[Donal]

So I have an ongoing issue with my HVAC system. When I turn on my heat on it blows cold air unless I set it to MAX (90 degrees). Happens on both sides of the car. If I turn it from 90 to 89 it goes cold. I saw a recommendation on here that it might be the blower motor resistor that was the problem, so I replaced that. Had no effect on the problem. I recentyly replaced the HVAC control, so I know it's not that... Any help would be appreciated!!

Probably need a scanner that can show live data and correct the system inputs and controls. Not sure if 03 has aspirators or if your vehicle has auto or manual conrols.

 

[strutaeng]

My 06 Suburban with the automatic HVAC control has this same issue. I've always thought it was controller itself. Additionally, in the first cold start when I turn the knobs clockwise the darn temperature turns colder intermittently! It's so annoying.

I once took the controller apart (while doing the LED conversion) and sprayed the knob with some deoxit and it seemed it made it work correctly for a few days. I don't have a scan tool with HVAC controls :-(

 

[Joseph Garcia]

@swathdiver

 

[Audball]

Probably need a scanner that can show live data and correct the system inputs and controls. Not sure if 03 has aspirators or if your vehicle has auto or manual conrols.

It has auto controls.
I've got a pretty decent scanner - I'll look and see if it has live data. Thank you.