Heater fan randomly turns off

[Matahoe]

Hello everyone. The other day after replacing the drivers side window motor on my 05 Tahoe I noticed my heater fan turning off for a few seconds and then comes back on and continues blowing like normal. It's got automatic controls. I'm also not sure if doing any work on the window motor is just a coincidence?

So with all the members knowledge I'm wondering if this is something easy like the resistor pack or is this maybe a common issue with something else like a bad ground or the fan itself? It seems kind of odd that it would be the resistor as those usually fail at a given speed, hense me being confused a bit. But then again I'm no vehicle electronics whiz so just thought I would ask here. Thanks a bunch folks.

 

[corvette744]

Hello everyone. The other day after replacing the drivers side window motor on my 05 Tahoe I noticed my heater fan turning off for a few seconds and then comes back on and continues blowing like normal. It's got automatic controls. I'm also not sure if doing any work on the window motor is just a coincidence?

So with all the members knowledge I'm wondering if this is something easy like the resistor pack or is this maybe a common issue with something else like a bad ground or the fan itself? It seems kind of odd that it would be the resistor as those usually fail at a given speed, hense me being confused a bit. But then again I'm no vehicle electronics whiz so just thought I would ask here. Thanks a bunch folks.

Could be many things take the cover below the passenger foot well off.Unplug the resistor see if you see melted wiring its common.If you haven't installed the updated one you will have to cut and splice the new connector inline with the new resistor.

 

[Matahoe]

Yeah i guess I could look at the resistor again. I replaced the wiring connector around 5 years ago when i replaced the head unit. i remember that cover under the dash taking a long time to remove due to obscure srews holding it up. I think I'll pass on that for now unless it becomes more frequent or bothersome. Im still open to any other opinions where to look easiest/first?

 

[OR VietVet]

Agree with @corvette744 about the resistor pack. By the way, on the poll, I checked all of them because I have replaced all of them.

 

[Tonyv__]

When my resister went out I only lost like one or 2 of my fan speeds but it worked on the 3rd speed. I don’t remember which one it was. But it was easy to diagnose that was the cause

 

[Fless]

When my resister went out I only lost like one or 2 of my fan speeds but it worked on the 3rd speed. I don’t remember which one it was. But it was easy to diagnose that was the cause

High speed is on its own fuse and bypasses the resistor circuits.

I voted but it was a neighbor's '04 Hoe on which I changed the resistor. Knock on wood, nothing yet on mine.

 

[corvette744]

High speed is on its own fuse and bypasses the resistor circuits.

I voted but it was a neighbor's '04 Hoe on which I changed the resistor. Knock on wood, nothing yet on mine.

Mine went out and not any speed worked.No air flow at all

 

[corvette744]

Yeah i guess I could look at the resistor again. I replaced the wiring connector around 5 years ago when i replaced the head unit. i remember that cover under the dash taking a long time to remove due to obscure srews holding it up. I think I'll pass on that for now unless it becomes more frequent or bothersome. Im still open to any other opinions where to look easiest/first?

Should take you less than 60 seconds to get the cover off lol.Thats no power tools either.I want to also add take out the resistor and see if their is any condensation or water on the back side of the circut board.Mine would intermittently stop and thats what i found was the problem with mine.This is the first place to look especially if its intermittent.

 

[Matahoe]

I have confirmed that the heater fan dies only when rolling up or down window. That's what I just replaced. Hmm. Starting to wonder if I have a battery/alternator issue. Going to check resistor and connector this evening.

 

[Fless]

You don't need to remove the screw that's above the hump, maybe just loosen it so you can swing the cover down and out of the way a bit. I would venture a guess that the electrical connector that goes to the resistor is damaged, melted, something like that.

 

[OR VietVet]

I have confirmed that the heater fan dies only when rolling up or down window. That's what I just replaced. Hmm. Starting to wonder if I have a battery/alternator issue. Going to check resistor and connector this evening.

If the problem only happens when rolling the window up and down, then if the window is the passenger side window, you did not supply that detail, I would still be interested in the wiring at the resistor since it is on the passenger side and some of the wiring conduit is likely shared and the window wiring goes thru that flexible conduit at the door jam.

 

[corvette744]

If the problem only happens when rolling the window up and down, then if the window is the passenger side window, you did not supply that detail, I would still be interested in the wiring at the resistor since it is on the passenger side and some of the wiring conduit is likely shared and the window wiring goes thru that flexible conduit at the door jam.

Yep put a test light on one of the power leads to the blower and or resistor and hit your power window switch-let us know what happens.Is your voltage gauge dropping when you hit the window switch.

 

[JonnyTahoe]

Should take you less than 60 seconds to get the cover off lol.Thats no power tools either.I want to also add take out the resistor and see if their is any condensation or water on the back side of the circut board.Mine would intermittently stop and thats what i found was the problem with mine.This is the first place to look especially if its intermittent.

After replacing my 200.00 Blower Motor Module, AC Delco P/N 15-8794 because of a 'surging' issue I just leave the Cover off and don't allow passengers up front.