2004 GMC Blend Door Actuator Replacement, Calibration & Comparison

In this video we look at my 2004 GMC drivers side blend door actuator. I have cleaned up the original actuator and it worked fine for 6 to 8 months or so. I decided to buy a cheap (eBay) replacement for it and change it out but unfortunately the span of movement from the manufacture did not seem close enough to calibrate. On the heat side it seemed so far out that I thought a look inside would be beneficial. I have the old and new side by side on the bench for comparison. We also go through the recalibration process toward the end of the video.
Video key points....
How to access the drivers side blend door actuator --- 0:00
Side by side comparison old vs. new on the bench ----- 4:15
How to clean the original actuator (common fix)------- 12:34
Recalibration of the new replacement actuator -----------17:45
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[@peterhodgkins6985]

Good dope right here!! These videos explain why the things go haywire if they're stroked while disconnected like my 96 C3500 was. I centered the pot, tossed a little fresh grease on the gears and presto - The air goes where the switch says it should go! Thanks so much for the info!!

[@-mj-]

Thank you for taking the time to make this video! Brilliant. I just wish I'd seen it before buying a replacement actuator (that displayed the same behavior as the one in your video)! Amazing. Well done, Sir and thank you!

[@ThriftyToolShed]

Michael Jackson, Thanks for your comment Sir!

[@jenniferwillhite7648]

Thank you so so much for your easy to follow video. I just changed my actuator out on my 04 grand prix and heat started working asap!

[@justinmartin3280]

Excellent video. Very well done and informative. I wish all how to videos were as clear and clean 👍

[@kendrichdanielssr4765]

Thank you very much for your video, i was able to go right to the task at hand and fix it. I will be one of your followers

[@ThriftyToolShed]

So glad it helped, thanks for your comment!

[@MegaHowtoMan]

Great video. I have same actuator on my 04 Tahoe. It drives to full hot always. I bought a Amazon replacement and it didn't fix it. I suspect a bad part. Now I'm going to try open the original and test it.

[@jimmarchman]

Very thorough. Thanks so much for this vid.

[@ThriftyToolShed]

Jim Marchman, Thanks for your comment.

[@thomaselliott4562]

Thank you! This was HIGHLY informative. Ordered a replacement tonight for my 2005 Buick LeSabre, essentially the same part. I went aftermarket on purpose since obviously the factory part failed. Maybe a different design will hold up better.

[@JeffMTX]

I got a BRAND NEW actuator, SK604100, from Rock auto. Didn't get a chance to put it on there til after 30 days- they won't take a return. Found your vid and it inspired me to look at that pot. I did, and it had a LEAD UNSOLDERED! BRAND NEW! You are THE MAN! MAGA from TX.

[@ThriftyToolShed]

Great job, thanks for your comment!

[@JeffMTX]

@@ThriftyToolShed My new vid might be of some interest. Tried to link it here but it seems to have been tossed out. It's on r u m b l e under 'Manipulating a HVAC actuator to make it work'

[@Lbcrow72]

Awesome..a lot of good info, thank you

[@Sheepdog_X]

Thanks, great guide on how to do this!

[@ThriftyToolShed]

SheepdogX, awesome, thanks for your comment!

[@tracylyons7715]

Very Very Good Video..Like the way you explained it..Thank You!!!

[@85preston]

Great video. Thank you for posting it. I have a 95 Buick riviera that uses the same actuator. I’ve cleaned up the one on it and it works sometimes but not always. Has anyone reading this tried this calibration on a different GM Vehicle? Thanks again and thanks in advance.

[@bingorn]

I bought one from Amazon and I will keep and fix the old one as described herein

[@larryfine4498]

Actuator on my 05 Silverado fails to relearn. Continues hunting in hot or cold position. I suspect a dirty or defective actuator. Will repost when solved. Great video

[@JeffMTX]

I had the same problem - solved rumble.com/vdqs0v-manipulating-a-hvac-actuator-to-make-it-work.html

[@kingknightable]

It def was that actuator,although it takes a minute to get to,because of the awkwardness of the screws,I haven't replaced my actuator yet but I did turn it from the bottom and opened it up by hand,my heat in the front automatically came on,thanks for the great info,I replaced thermostat for nothing

[@ThriftyToolShed]

kingknightable , Glad it helped and thanks for your comment. And hey now you have a brand new t-stay also! : )

[@DaveSender66]

Thank you for sharing your experience with us! You have helped me !!!!

[@ThriftyToolShed]

DaveSender66 , Glad it helped, thanks for your comment!

[@chadpugh1490]

Got the same cheap replacement. Mine went out of range as soon as I started the car. Now it won't go back. The manufacturer is telling me it's because I plugged it in and started the car without it installed on the spindle. They're sending me a FREE replacement.

[@gfunkkowboy]

Good job brother

[@emmettturner9452]

Bought the blend door and mode door actuator for my 2000 Pontiac Montana when I was getting clicks. Blend door turned out to be fine. The clicks were from the fresh/recirculate mode door actuator where one of the gears was cracked. It will settle and won’t click depending on your mode selection. Are you sure the fresh/recirculate mode actuator wasn’t what caused your clicks? That said, the instructions said not to connect/disconnect with the key in place so that it will not skip that homing process that happens every time you turn the vehicle on.

[@leewalker3514]

From one Georgia boy to another thanks it works

[@bryandiel6773]

once a new actuator is installed you must pull hvac eac 10 amp fuse, leave out 10 minutes, reinstall start engine turn on AC let the motor run a few minutes, it will got through the split, mid defrost modes, when it is done, shut of engine. wait 2 minutes, restart engine, turn on AC should work fine, the ECU will self calibrate the actuator. Google your procedure depending on split controlled or auto AC, before you fuddle around needlessly

[@briarz101]

have a '94 Silverado, had a '95 GMC, both went bad, gear split. this is an '04?? Can't believe they didn't fix these issues within that amount of time. very common, not easy to get to to replace, not cheap either

[@elmono3939]

Great ! Ok so I purchased brand new AC door, put it in, and it goes all the way to the one end - and recoils about 1/4 way back. Never stays all the way in full cold or hot. It is brand new unit. I called the store I bought it from, they tell me it is "plug 'n' play" device. Any suggestion ?

[@ThriftyToolShed]

The calibration procedure is all I would know to try on this after install if it doesn't work properly.

[@MeganBlazeiko]

Ive come across your video and im having the same problem with my 2004 sierra with the same actuator as the one you bought with it going to far but it will not always go back the other direction when move the drivers side heat control. I pulled the fuse and did recalibrate it the first time everything was recalibrating (could hear it) I waited 10 mins turned on truck and It still giving me just hot on drivers and cold on passenger side. I bought another actuator ( same exact one) thinking something is wrong with the first one. Still having the same problem with that one. I’m completely stumped and don’t know what else to do or what the problem could be. Any ideas you could give me?

[@ThriftyToolShed]

That is what I did to get mine recalibrated. I no longer have that truck, but it worked after that for quite some time. I don't know how well the cheaper ones will hold up long term, but it's odd you are having issues with 2 of them. It does cross over to the same GMC p/n correct?

[@MeganBlazeiko]

@@ThriftyToolShed yes it does. After I recalibrated it I turn on the truck it goes from cold to hot stays on hot when it should be on cold, then I turn off the truck turn it back on it goes back to cold and then right back to hot and will not go back to cold.

[@ThriftyToolShed]

Sounds weird, I found this also for steps on recalibrating. Since I have not done this in over 5 years. sparkys-answers.com/2011/08/hvac-actuator-recalibration-procedure.html

[@MeganBlazeiko]

@@ThriftyToolShed thank you!

[@skiprope536]

Typical Engineering Failure. Remember days of cables guys. My 70 GT 37..For those of you it was a Pontiac Tempest with400 Cid Ram Air. 345HP. Cables where great. You move a slider that had a cable. Heat, Defrost, and you blended the Temperature anywhere you wanted it to be. all this other shit is pure nightmare. My blower stooped it is the fan relay. more crap to take apart. Good video. But dude. You get what you pay for.

[@birdwing98]

Yes, I remember those good old days. Levers pulling on cables never gave me any trouble. I had a newer style from GM that had a lever, but it switch vacuum signals through a complex manifold/switch. After many years the plastic wore so much, there were vacuum leaks in the multiplexor/switcher that it had to be replaced. Forgive me for not knowing the correct name for the vacuum control brain. Never had a problem with the vacuum actuator.

[@mitchputerbaugh1940]

What does this control? What symptoms did you have for you to know this was bad?

[@ThriftyToolShed]

My original actuator was "hunting" or constantly moving back and forth you could hear it as well as the temperature was not correct, blowing warm even on cool.

[@hanluong2510]

I have no power to the plug ok with the old one but after installed the new one the plug has no power. would you help me Thanks.

[@joerossi43]

After taking my actuator apart, I think the manufacturer purposely put a dollop of grease on those copper fingers that ride on the inductors looking track contacts

[@danielboyd1186]

Dielectric grease is good for electrical contacts.

[@josevasquez6497]

my 2005 chevy suburban does not change from hot to cold on the driver side it is hot all the time and on the passenger side if it changes

[@odiarroyo6144]

Do the recalibration

[@foxdiaz4596]

@@odiarroyo6144 how do recalibration?

[@adventuresofmattyb1386]

You probly made it go out of alignment on your own you are not supposed to turn those on and power them up until they are hooked to the bland door

[@ThriftyToolShed]

Thanks, but it was hooked to blend door first!

[@foxdiaz4596]

How much the peace?

[@erin19030]

There is no calibration. It's a continuous rotational motor , forward and reverse. All you need do is make sure the replacement motor shaft is in the same rotational position of the original motor. That can be done on the test bench , simply with a 9 volt radio battery and two jumper wires, utilizing a small protractor. Since the shaft is not keyed , you can get it put of position by 180 * and still get it right.

[@TAMBestBuild]

There is a blend door actuator calibration procedure that requires pulling the fuse and an engine timed on-off sequence. Google it.

[@ThriftyToolShed]

Cosimo Kramarawicz, you are incorrect!

[@larryfine4498]

You are incorrect. Advanced obd scanners have a relearn option that uses the ECU to reset the actuators. His procedure is a workaround to not having a scanner.

[@rahrah8076]

Cosimo Kramarawicz yeah this video will show you kzbin.info/www/bejne/rIileH6coZyeaJY

[@justinstandifer604]

@@ThriftyToolShed I just replace them & they work. They actuators have stoppers in them(at least the mode door one does). Never had a issue. My old one wouldn’t switch to defrost because the gear was cracked.

[@sonofthunder.]

cut the boot guard w cut off wheel easier access to screws,popped open,has no little green gear,seemed to be out of sync,...recentered reinstalled all good 05 gmc sierra 6.6 2500,...recalibrating wasnt working for me ,anyhow its fixed for now little super glue on the clamshells,keeps it tight,...i had just replaced batteries(diesel) when it got outa sync

[@ChiDraconis]

Before attempt try antioxidant on the connector

[@ThriftyToolShed]

Connector is never been an issue on mine, almost always the on board variable resistor for feedback as mentioned. Even though the grease is most likely supposed to be there, once the wear on the resistor turns into powder and mixes with the lube, it's got to go. Causes feedback issues.

[@ChiDraconis]

@@ThriftyToolShed Okay I will go with that; One of the mount screws I think is hard to get to; My shop has an extensive ¼" drive collection • do you know the socket size and if it is metric or SAE?

[@ThriftyToolShed]

At around 15:57 I mention that mine are 5.5mm or 7/32 and a small thumb rachet is very helpful.

[@ChiDraconis]

@@ThriftyToolShed Okay noted; Thank you;

[@stillwill1808]

Shayzuskeyrist! You gotta find a better place to get your parts than e-bay

[@ThriftyToolShed]

Believe it or not I even know how to search and find parts on my own. I think it's places called dealerships, maybe RockAuto and maybe at least 1 other place in the world to get parts they are so rare... Not like we have autoparts store on every street corner or anything. I actually did this for video purposes. I recorded it myself also...

[@pedroadriano9183]

What does an engineer say to the basic stuff and not designed garbage

[@blackholeofeternity7908]

Passenger side buddy not drivers side. Doye

[@plastite]

Stupid electronics! What is wrong with cables ? like on my old 72 GM truck. Repair shop charged me $500. to fix this on my 2003 GMC.

[@ThriftyToolShed]

Wow!

[@blackholeofeternity7908]

They raked your yard

[@joerossi43]

After taking my actuator apart, I think the manufacturer purposely put a dollop of grease on those copper fingers that ride on the inductors looking track contacts

[@ThriftyToolShed]

joerossi43 , it's typically a resistive track alot like a potentiometer. I had luck twice with mine after cleaning the gear grease off the tracks, but maybe they do? Anyone else out there seen the same thing?

[@birdwing98]

@@ThriftyToolShed It's counter-intuitive, but I've seen dielectric grease applied to the microphone jacks inside a Public Address system. The grease eliminates the cracks and pops when the cord is wiggled. I know the volume controls on an old radio were potentiometers with a wiper, and if they got "scratchy," the fix was some type of aerisol cleaner.

[@ThriftyToolShed]

@@birdwing98 Yes I totally agree, I have seen it and I have used it.I believe it is when the carbon track gets worn like mine and the grease is dark because it is carbon filled and now conductive. When I clean one like that I am really just cleaning off the darker grease, and it has worked every time when one is hunting back and forth for position. To my other point I have work around dc motors for over 25 years and we let carbon and copper glide together and the carbon is the lubricant. That is why I am not sure if the grease was meant to be on there or if it comes from the gears?

[@Newman81964]

@@ThriftyToolShed The dielectric grease is not on there as a gear lubricant, it is there to protect the electrical connection.

[@ThriftyToolShed]

Although I am very familiar with protective non-conductive grease, it's not a problem unless the carbon dust from track wear builds up and it's conductive! Mine lasted about 6 months after cleaning well so I had a replacement on hand before it started hunting again. If course the grease that was "from the gears" had gotten on it even though I had cleaned the track well 6 months earlier.