# Drivers side of truck blowing out cold air...



## mkwl (Jan 21, 2005)

Well, on my trip back up to college last night I discovered that my '06 Duramax's drivers side heat is not working. With the fan on, and both "sides" of the manual climate control all the way up to max heat, the passengers' side blows out blazing hot air, but the drivers' side is ambient temperature (cold). Any thoughts on this? Is it something with the control (manual) module, or something else? I really want to get this figured out because it's starting to get cold up here!

Thoughts?

Thanks,
Matt


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## Q101ATFD (Oct 24, 2006)

Sounds like the drivers side temperature actuator is acting up. What's happening is the actuator is not calibrated to the position of the slider on the HVAC control. Sometimes there is a clicking noise associated - this is the actuator attempting to over-travel it's limit. There is a TSB on this issue that calls for a software update. Your dealer will probably charge you 1 hour of labor for the re-flash. If the problem just started, take it to the dealer sooner than later because the plastic gears in the actuator will strip out easily.

See the attached file for more information, and mention it if the dealer tries to tell you something else is wrong or tries to up-sell you something.


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## brad96z28 (Aug 21, 2005)

I change plenty of actuators.


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## mkwl (Jan 21, 2005)

Is there any way to "reset" the actuator other than spending $120+ at the dealer (maybe fixing the problem)? Like pulling the HVAC fuse for a couple mins?

If I simply replace the actuator, will that fix the problem, or does it have to be dealer programmed to work?

Brad- where is the actuator for the drivers side vents located? Hard to replace? Cost (of parts)?

Thanks guys!


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## mkwl (Jan 21, 2005)

Q101ATFD;1102355 said:


> Sounds like the drivers side temperature actuator is acting up. What's happening is the actuator is not calibrated to the position of the slider on the HVAC control. Sometimes there is a clicking noise associated - this is the actuator attempting to over-travel it's limit. There is a TSB on this issue that calls for a software update. Your dealer will probably charge you 1 hour of labor for the re-flash. If the problem just started, take it to the dealer sooner than later because the plastic gears in the actuator will strip out easily.
> 
> See the attached file for more information, and mention it if the dealer tries to tell you something else is wrong or tries to up-sell you something.


I'm not hearing any clicking- it just doesn't blow out hot air- just blows out room temp air 

I believe my '03 has the same HVAC system (same dash controls)- would it make sense to try swapping the actuators to see what it changes?


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## WilliamOak (Feb 11, 2008)

didnt you get a warranty with it? hand it over to them then lol.


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## Q101ATFD (Oct 24, 2006)

You can pull the HVAC fuse to reset the HVAC system, but that won't guarantee that it won't happen again. What happens is the HVAC module sometimes loses track of the position (open, closed, and everywhere in between) of the actuator, and causes it to over-travel it's physical limits which is what causes damage if the software is not updated soon.

Changing out the actuator won't permanently fix the problem unless you get the software update from the dealer too. Sometimes if you take it in and ask to make sure you have the most up to date flash, they'll do it for free - but 1 hour at $95 (I think) at the most.

The part number is 89018365 for the drivers side actuator - I found a new OEM on one eBay a few weeks ago for $80. It only takes about 10 minutes to change out - it is located under the dash, just to the right of the center hump. There is a 5-wire harness that plugs into it.


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