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Ask Gm Tech (Cam) Your Own Question
Gm Tech (Cam)
Gm Tech (Cam), GMC Mechanic
Category: GMC
Satisfied Customers: 29427
Experience:  GM Grand Master Technician 2007. 14 year experience.
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I have a 2006 GMC YUKON DENALI XL with over a 150k and it

Customer Question

I have a 2006 GMC YUKON DENALI XL with over a 150k and it been excellent truck, but now the air conditioning/ heat isn't blowing out from the vents, I replaced the digital climate forward control thermostat (the full digital type not the one with the slides controls) module and it still no air conditioning blows through the top vents, my rear air and heat works but not my front. I bench tested the blower motor and it work fine under direct power (I made a mistake and removed the wheel off thinking it might have been gummed up but didn't mark the position it which it came of in but I guess that I will have to figure that after I figure out why it not working)
JUST ANSWER has my account completely messed up and have me posted as a expert on my own question so I have no be able to interact with a mechanic on this as it goes no where and I cannot communicate hopefully the have it straighten out.
Submitted: 1 year ago.
Category: GMC
Expert:  Gm Tech (Cam) replied 1 year ago.

Hi there, I am Cam. Can I get your first name please? With your unit, you said the blower works but you cannot control where the air blows? Am I understanding this correctly?

Customer: replied 1 year ago.
My name is ***** ***** And you have been kind enough to help me out on previous questions before Cam as a matter fact he tried to help me yesterday or the day before and just answer completely messed my account completely up and had me rated as a pro expert and would not let me interface with you with a response to the question.The air doesn't not blow at all and on the rare occasion is does it trickles, and the forward air does NOT work, the rear air does. I have replaced the forward control unit (that controls everything underneath the radio and it didn't help) I bench tested the blower and it works but on the bench not installed, there's power to everything, the AC unit under the hood 'sweats' and will pool water somethings, when you try to use the a/c it just make a repeated clicking noise for a couple minutes and then stops and if I try to adjust the settle in certain mode the air never blows but the clicking noise comes up sonetimes - like I said I bench tested the blower and didn't realized I wasn't suppose to pull the blower wheel off but I did and didn't mark it position but I can deal with that later it wing be at the right speed, I'm suffering down here in Florida
Customer: replied 1 year ago.
Replaced with new unit
Expert:  Gm Tech (Cam) replied 1 year ago.

Understood Paul, so my 2 thoughts are first, the blower is not working the vehicle or the mode is incorrect. You tested the blower and that is fantastic, so next, when you had it installed and the vehicle turned on, did you feel the blower motor working under the dash? If not then do you have a test light?

Customer: replied 1 year ago.
Replaced it by part number and even tried to go back to replace on to see if it made a different and it didn't - but I did replace to GM oem number and I didn't test the blower motor in the system I pulled it out and bench tested it, and yes I have a tested light and I doubt check the power and everything gets full power
Expert:  Gm Tech (Cam) replied 1 year ago.

OK, you replaced the heater control head, I am thinking its the blower motor controller beside the blower motor. Does the coloured wire from the controller to the blower motor have full power that changes with blower speed?

Customer: replied 1 year ago.
I don't know it this has anything to do with the problem I think it does ??? Before the system went completely wacky you could here the vents hissing well after the air was shut off and even after the retained electrical power was used (15 mins) on occasion I could disconnected the neg on the battery and it would still hiss or if j was getting I the car and the front air wasn't working on a hand full of time I could 'reset' the set but disconnect the battery for 15 sec but this work 3 or 4 times ? I read online about a replace a resistor ?? And that is the 2nd leading problem next to the a bad control assemble and I read that on Chevy Tahoe forums ??
Customer: replied 1 year ago.
With the test way I can only tell if it has one speed and it does have Power going to the purple wire which goes right underneath the blower motor and it seems to have power and all the directions I haven't pulled the entire unit out I don't know if the blonde where's your stock which is also what I read which cannot return or can be true or the resistor or other problems that they have it seems like it wants to work when you engage the blower motor collects and keep cooking for about 30 seconds and then it stops and won't engage
Customer: replied 1 year ago.
Would the resistor that I'm speaking of that you probably know more about than I ever would control that high low on the board motor and give a variation of speed because when I tested our bench tested the blower motor obviously I can only get one speed out of it so if there is another component that needs to be replaced that would probably be yet in between The new climate control head that I tell it what I want to polish need to be and the blower motor there's something in there that's not working right so I would agree with you that that's probably the problem and that quick then I keep hearing is probably it trying to work but not working if that makes any sense to you
Expert:  Gm Tech (Cam) replied 1 year ago.

the blower controller is also referred to as a resistor pack, but with yours, the automatic system, IT is the blower motor controller. The difference is 7 wires in for manual systems vs 3 for automatic systems. And yes, that controller is know for causing issues that keeps the blower motor running after the key is off. The more we talk, the more I think it is that blower motor controller beside the blower motor that is causing the issue.

Customer: replied 1 year ago.
is that blower motor the part that I just replaced I need when I called the climate control head or is this the part that I bench tested or is this a completely different part?
Customer: replied 1 year ago.
Because I have to wear those control heads and neither one of them works I have the old one that I replaced and I have a new one that I just bought and neither one of them is doing the trick so if it's a third component then I would tend to believe that you're right I wants I have got a bad one off the shelf and that's the picture that I sent Before I replace that unit twice the regional and then I got another one and I tried to interchange them at different times but it doesn't know what doesn't work either so before I replace that unit twice your regional and then I got another one and I tried to interchange them at different times but it doesn't know what doesn't work either so if that what you're calling the blower motor that component that I sent you a picture of? Or the actual blower motor that goes up and into the van that has the wheel on it? Or is this a third component?
Customer: replied 1 year ago.
I have the whole thing pretty much torn apart with the only exception is so I can drive it it's not completely torn apart is there anything that I could check or any other suspicions that you may have or ??????
Customer: replied 1 year ago.
This is from something one of your colleagues wroteWhen you are satisfied with my answer, Please click ACCEPT. Positive feedback is always appreciated.
Well, with these guys it is one of two things.
1. The a/c control head is the cause 80% of the time.
2. The blower motor resistor or wiring to the resistor is the cause 15% of the time.
3. The last 5% divided between the blower motor & wiring issues & both are rare.Read more: http://www.justanswer.com/car/19i0z-2005-gmc-yukon-front-a-c-wont-blow-rear-does-work.html#ixzz3o6JG9rVI
Expert:  Gm Tech (Cam) replied 1 year ago.

If I may be honest, I do not agree with what that expert put. first off, there are 4 possible issues. First, wiring. Second, the climate control head or climate control module (you replaced that already), third, the blower motor itself ( You tested and its good) and fourth the blower motor controller mounted beside the blower motor. ITs actually rare the the head is bad. The motor is common, the blower controller is VERY common and wiring is not common.

Customer: replied 1 year ago.
is the blower motor controller a separate part that I haven't replaced yet? And I was pretty sure that it was the complete unit because when I took it apart to look at it there was some burnt fuse link o so is the blower motor controller a separate part that I haven't replaced yet? And I was pretty sure that it was the complete unit because when I took it apart to look at it there were a couple of birthmarks at the very top of the ball or more control but that's what it all apart so I don't know I haven't taken the one I just bought apart so you think it's the blower motor controller ? How can I look at them and see if that burn or if it's bad wanker if yours something that I missed, about a year ago I had to jump the orange wire from the pack blower to where it goes into the fusible link behind the brake pedal on the emergency brake panel because it was all burnt up with in the plug so I dug it out and connected it straight and it hasn't given me a problem ever since, but I don't think that would have any affect on what's happening today but I figured I would mention it so you think it's the blower motor control or where would I find that and is there a way for me to check it?
Customer: replied 1 year ago.
Or is that the part that you said is in my replaced climate control unit as to where it seven wires as opposed to three or four wires and already has that system in it?
Expert:  Gm Tech (Cam) replied 1 year ago.

Correct, the blower is independent from the blower controller.

First picture shows the blower motor controller.

Expert:  Gm Tech (Cam) replied 1 year ago.

This shows blower motor (right) and controller just to the left.

Customer: replied 1 year ago.
If I remember correctly that uses 7/16 socket and I think it's I know one as an actuator is that the one right before/underneath the blower motor and you feel that that's the part because I did tested and it is getting electricity but obviously I can't you know I pulled it out and it looks to be two or three things and now I'm not quite sure what it
Expert:  Gm Tech (Cam) replied 1 year ago.

No, that is 5.5mm socket, much smaller.

Customer: replied 1 year ago.
I may be wrong about it but when you pulled out there's two or three 'fins'
Expert:  Gm Tech (Cam) replied 1 year ago.

That is exactly the correct part. Those fins are a heat sink.

Customer: replied 1 year ago.
you think that's it? Is there more then 1 of these in the system ?
Customer: replied 1 year ago.
While I'm talking to you there's another part that day attribute this problem to what is called a resistor block or do you think that we fundamentally have the problem, I don't even know what that resistor block would go or is that the one that is already with in did The digital climate control?
Expert:  Gm Tech (Cam) replied 1 year ago.

There is one for the front blower and one for the rear but that is not in question. What you are calling the resistor block is that controller you pictured. And seeing the rust on it, I think its been wet and that does shorten the life.

Customer: replied 1 year ago.
Tell when your best guess do you think that's the answer? And I can't order one of these from anybody besides the dealer can I? Do you have an OEM part number so I can try to run out and get one of these and is there an installation procedure or just pop it in and that's it? Because if you think that's the problem it would make a lot of sense and yes one of them was extremely rusted just condensation is been building up there for nine years
Customer: replied 1 year ago.
Do you have a GM part number and I can't get this at Napa it's a dealer only part
Customer: replied 1 year ago.
Correct?So in your best guess that would be it?When I pulled the blower I separated the blower wheel from the blower and I didn't mark position am I going to have to fight when with it to get the speed right as I saw the speed is mark along the inside or does that even matter ?
Expert:  Gm Tech (Cam) replied 1 year ago.

YEs, if this was my vehicle, or I was working on it, and with all your excellent information, I am 99% sure its that part. I would get an AC Delco from GM, and I do not have a current part number. There have many updates so numbers change. As for the blower and wheel, you might end up replace the motor assembly due to that. They are not really meant to come apart.

Customer: replied 1 year ago.
It came apart very easily and spun freely the reason why I ask if there is a method to putting. The two back together is because on the inside there is a bunch of numbers 10,30,30,49 which I gather are speeds is there a way of recombining them or it going to be trial and error? What EXACTLY do they call that part ? ;they one that needs to replaced I would call it a actuator but I don't think that correct? There is a metal staple hooked to the blower wheel but I could find a mark on the motor assemble telling me if there is a line up procedure ?
Expert:  Gm Tech (Cam) replied 1 year ago.

The wheel is not meant to come off, so if it goes back on then its ok. The staples are to balance the wheel on it. ITs properly called the blower motor assembly.

Customer: replied 1 year ago.
That part that I spent you pictures of us called the blower motor assembly ? I headed to the dealer now
Expert:  Gm Tech (Cam) replied 1 year ago.

No, the part with the metal fins is the blower motor controller.

Customer: replied 1 year ago.
Just a curiosity according to Hayes which I don't put much stock in them on section 3 page 8 they have a blower motor resistor terminal guide which controls the output speed to the blower motor but you said that we've already gone by that because we have the digital climate control child is no point in even going to that as it doesn't exist because ours is the one with the fins correct ?
Expert:  Gm Tech (Cam) replied 1 year ago.

Haynes manual is wrong.

Expert:  Gm Tech (Cam) replied 1 year ago.

\Any updates?

Customer: replied 1 year ago.
Cam - thank you for all your help I just went to the Chevy dealer because it's the closest one to me and I swear he gave me the wrong part and I even had a technician tell me that was the right one I'll send you some pictures of it I guess it was an upgraded part to where you now have to splice and disregard the 3 wire set (not the ones to the blower motor the front set as your looking at it) I did as the instructions stated and it's not working for me
Customer: replied 1 year ago.
Any thought on this ?
Expert:  Gm Tech (Cam) replied 1 year ago.

OK, so its not working. that is the updated part. So lets review a bit./ into that you have the thick orange and thick black wire, correct? Do those get power all the time on the orange and have a good ground signal on the black? If not check the blower fuse in the underhood fuse block.

Customer: replied 1 year ago.
I go back thru when I home - I must be doing something wrong in haste with my $169.0O AC DELCO 'CHINA'
Expert:  Gm Tech (Cam) replied 1 year ago.

OK, I Am not sure where you are at now. I would urge you to consider the phone call, I get the feeling it will help a lot on this.