HVAC controls not telling blower to turn on, intermittent

[hillstrubl]

Wife texted me saying the 2011 Tahoe we bought recently isn't enabling the front blower fans, but rear controls worked fine.
I got in today and everything is fine. Should I pull the dash apart and make sure there isn't anything obvious or is an easier check to pull the HVAC fuse and wait a bit?

 

[My73tahiti]

Following this. Same issue, replaced the resistor. It’s getting 14v. How do I test the blower motor?

 

[TJFHUNTER243]

Wife texted me saying the 2011 Tahoe we bought recently isn't enabling the front blower fans, but rear controls worked fine.
I got in today and everything is fine. Should I pull the dash apart and make sure there isn't anything obvious or is an easier check to pull the HVAC fuse and wait a bit?

FOLLOWING FOR SAME ISSUE WITH MY 07

 

[02Lightning]

I replaced the front blower resistor in mine, and the bower will stop for no reason, then start back up. None of the wires to the resistor looks like they have been hot or anything. So, looks like I'm in the same boat.

 

[hillstrubl]

Currently doing it again. The rear controls seem to work fine. I can get a small amount of air to come out if I have the rear on and recirculating disabled. It's like the blower isn't getting the message to spin up. Any ideas? Should I just take the dash apart?

 

[02Lightning]

I just replaced my blower motor, and it didn't help.

 

[hillstrubl]

I just replaced my blower motor, and it didn't help.

I don't think its the motor for mine anyway, its like its not being "told" to engage. I might try to source a used control panel first.

 

[Doubeleive]

if any of you have a tech2 you could try commanding the fan on when this happens if it does not respond or does respond but the controller won't change it alone. then I would certainly suspect the controller.
also check for any hvac system codes. blend door feedback codes are very common but most likely not the issue in this case.
you could also maybe check and see what the comanded state of the fan is versus actual. (if there is such a option in the tech2)
mine is in the shop for a couple more days so I can't offer much more help at the moment.

***also I assume all of you have the digital control? or is this happening with the manual controls also?

 

[02Lightning]

I don't think its the motor for mine anyway, its like its not being "told" to engage. I might try to source a used control panel first.

A digital control pannel will need programed to work.

 

[02Lightning]

if any of you have a tech2 you could try commanding the fan on when this happens if it does not respond or does respond but the controller won't change it alone. then I would certainly suspect the controller.
also check for any hvac system codes. blend door feedback codes are very common but most likely not the issue in this case.
you could also maybe check and see what the comanded state of the fan is versus actual. (if there is such a option in the tech2)
mine is in the shop for a couple more days so I can't offer much more help at the moment.

***also I assume all of you have the digital control? or is this happening with the manual controls also?

I do have access to a tech2, but mine only happen randomly for a few a seconds.

 

[Doubeleive]

I do have access to a tech2, but mine only happen randomly for a few a seconds.

Like every drive? once a week? how often, maybe hook up the tech2 and command the fan on high and see if it changes while driving. not sure if you can drive record the fan speed
@swathdiver ?

 

[02Lightning]

Like every drive? once a week? how often, maybe hook up the tech2 and command the fan on high and see if it changes while driving. not sure if you can drive record the fan speed
@swathdiver ?

Twice in and hour drive, then not again for a week.

 

[Doubeleive]

Twice in and hour drive, then not again for a week.

unless there is a hvac code saved then that one is going to be hard to track down until whatever it is just quits period.

 

[02Lightning]

unless there is a hvac code saved then that one is going to be hard to track down until whatever it is just quits period.

Only pending code I see is a B0433, but I don't think it's related and not a hard code. Next thing I'll do is look at the plugs and try and bend some prongs for better connection.

 

[Doubeleive]

Only pending code I see is a B0433, but I don't think it's related and not a hard code. Next thing I'll do is look at the plugs and try and bend some prongs for better connection.

b0433 is the rear hot/cold blend actuator, would not affect the fan

 

[02Lightning]

b0433 is the rear hot/cold blend actuator, would not affect the fan

Yes, understood

 

[swathdiver]

Like every drive? once a week? how often, maybe hook up the tech2 and command the fan on high and see if it changes while driving. not sure if you can drive record the fan speed
@swathdiver ?

Should be able to using snapshot feature.

Have you guys checked those little aspirators in your headliner? They can get full of lint/hair and stop reading correctly which will confuse the climate controls.

 

[02Lightning]

Should be able to using snapshot feature.

Have you guys checked those little aspirators in your headliner? They can get full of lint/hair and stop reading correctly which will confuse the climate controls.

How do you go about doing that?

 

[swathdiver]

How do you go about doing that?

If asking about the aspirators, pull the little speaker covers off and have a look up in there. Use a pick, Q-tip- vacuum cleaner, etc. to clear the fan blades if they are clogged. If the fan is dead, you can drop the headliner a little and replace them from the side. @Doubeleive Wes has more experience with these than I do, I think!

 

[petethepug]

Preloved digital control panels from other vehicles do not need to be programmed if you’re going to replace it.