GMC Chevy Blend Door Actuator Repair Replacement Fix Constant Heat Cracked Gear J-B Weld Repair

Replacement Blend Door Actuators on Amazon - amzn.to/2EiD8sH
Blend Door Actuator Gear Rebuild Kit on Amazon - amzn.to/2N9IdpP
J-B Weld on Amazon - amzn.to/2N0zTc8
This video covers the process of repairing and replacing, the electronic blend door actuator on a 1998 Chevy Blazer. The process covered in this video will be the same on many other Oldsmobile, Chevy, GMC, and Pontiac vehicles. When the blend door actuator fails you may notice constant heat air, constant cold air or hot and cold air may toggle back and forth if the computer is trying to learn where the blend door is. This video also provides a close-up view of the blend door actuator in correct synchronization. The blend door replacement and repair process is the same whether working on a manual heat control or the automatic temperature control (computerized climate control) in General Motors vehicles. I used JB Weld to repair the cracked blend door actuator gear in this video. How to set the timing on a GMC blend door actuator.
Replacement Blend Door Actuators on Amazon - amzn.to/2EiD8sH
Blend Door Actuator Gear Rebuild Kit on Amazon - amzn.to/2N9IdpP
J-B Weld on Amazon - amzn.to/2N0zTc8
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Mark Jenkins is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com
Disclaimer:
Due to factors beyond the control of Mark Jenkins, I cannot guarantee against improper use or unauthorized modifications of this information. Mark Jenkins assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. Use this information at your own risk. Mark Jenkins recommends safe practices when working on vehicles and or with tools seen or implied in this video. Due to factors beyond the control of Mark Jenkins, no information contained in this video shall create any expressed or implied warranty or guarantee of any particular result. Any injury, damage, or loss that may result from improper use of these tools, equipment, or from the information contained in this video is the sole responsibility of the user and not Mark Jenkins.

[@nogripes]

Replacement Blend Door Actuators on Amazon - amzn.to/2EiD8sH Blend Door Actuator Gear Rebuild Kit on Amazon - amzn.to/2N9IdpP J-B Weld on Amazon - amzn.to/2N0zTc8

[@22kpar1xcyberdyne9]

Took me 30 minutes to find your video from sorting through all of the hack videos. This is quite possibly the BEST do it yourself VIDEO I have ever watched on youtube. Fixing a 2000 trailblazer today. I applause the use of jb weld, hose clamp, and cutting new splines.

[@charlieb2794]

Awesome video! Thank you. All your videos have kept my 1999 Blazer on the road

[@nogripes]

Great to hear!

[@kevinhenry61]

😂 I have to laugh as I was about to post a positive comment on your presentation only to find I commented 6 years ago when this originally happened. Only difference now is it's -35C and my blend door takes about 45 minutes to switch to defrost for the windshield. Needed a refresher course. Thanks again.

[@TraciMadisonVoice]

Mark, you are a Rock Star!!! You nailed this video with all the right tips. No surprises and I'm so grateful.It's -20 degrees up here in Canada and had no heat, until your video came along. From freezing to Cooking Hot! Can't thank you enough! Keep them coming. I love my Envoy and can't part with her. That's right everyone Mark has acheived Official Rock Star status!!

[@thomasbuss7671]

Awesome video. Thanks! My Jimmy was only blowing HOT air. I got a written estimate from the dealership where I bought the car. They quoted me $320 for the part and 9 hours labor for a grand total of $1220. No thanks. I got a blend door actuator from the local pick a part for $20 bucks and wouldn't you know it, the big gear was also cracked but not all the way from the gear's teeth down to the pot metal pin that it is pressed onto. I swapped out that gear and it had been working for about 3 years but now it's stuck on only blowing hot air again. I was going to bypass the heater core for the summer but instead, I removed the actuator and moved the blend door by hand. That will work until I get another actuator. All I did to gain access to the actuator was to drop the glove box. If a person has big Popeye like arms and big hands they probably wouldn't be able to get at it without doing a bunch of dashboard removal like the dealership would have done. Thanks again so very much for taking the time and effort to create the awesome video. Happy wrenching!

[@robmitc7]

Best video I've seen. Gonna order this right now for my hot air issue. Thanks

[@booloc5762]

dude you rock man.helped me out of a big pickle.keep doing videos like this!🖒

[@meanolmeany]

Excellent tutorial. You did skip step one: have baby sized hands!!! Thanks, dude.

[@kevinhenry61]

Thanks for the information. After spending $200 at the local Air Conditioning "Experts" they couldn't figure out the problem. I spend an hour on KZbin,follow your advice and remove the actuator and my gear is cracked. I open the blend door manually and voila I have cold air again. All this after suffering through the hottest summer on record locally, without AC.

[@mrdrh99]

Very very helpful! I haven't even done the repair, but I was worried about not having ac this summer. After removing the actuator, I was able to manually turn the post that switched from heat to cold! Whew! And those 2 screws are no joke! Thanks a ton, and I'll reply to my own comment on the how the repair goes!

[@graymule72]

works like a charm ! i decided to buy a replacement gear from flea bay instead of taking my chances with the j b weld but your instructions were spot on.

[@Houseofhaha]

Thank you! We were able to fix out 2000 Chevy Blazer thanks to your video. Great job explaining everything in the video.

[@georgewerrbach3986]

“Son of a B, Mark!” “Would be lost without your S-10 repair vids!!” “Took blend door actuator out!, and sure enough!, “Cracked exactly like yours!!” “Thanks so much!!” “You are as valuable as any other tool in my box!” George from PA. 2003 4.3 Blazer

[@gregsewell4259]

Nice video. Like you mentioned, it is important to make sure the track guide is clear of any JB Weld so the gear will turn smoothly. However, when filling the cracked gear you can go ahead and fill over the outer toothed area of the gear with JB Weld, as long as you install the fixed portion away from the remaining gears. That's because when the metal piece is placed back inside the gear, and the gear is installed back inside the unit, the gear will only turn 180 degrees in each direction. Because of this, the glued toothed portion never makes contact with the teeth on the other gear. So go ahead and glue over the toothed section of the crack for even added strength, but just make sure you still leave enough room for the gear to turn while inside the housing unit, and also remember to MAKE SURE you install the cracked portion away from the other gears when pressing the metal portion back inside the repaired gear.

[@so4reel2]

Thanks for the help. Great video

[@ussconcordiah9506]

Perfect video! with this, I discovered that the drivers side temp actuator is seized. Headed to junk yard this weekend to pull one of an old GMC envoy and swap it out.

[@wildcatcreeksurvival2414]

Hey Mark, repaired BDA on my 98 Jimmy thanks to your clear and concise video. I went the JB Weld route and it took 2 days but I would have been lost without your instructions. Very tough getting this unit out and back in, but A-OK now! Subbed

[@talpash]

Didn`t want to tackle mine , but after watching the video, I have a bit more confidence ! Thanks

[@MadBadgerCR]

Great video man!!!

[@johncoate9964]

Excellent video and instructions! Thanks much for sharing your time and expertise. Much appreciated:)

[@BretLafty]

Thank you great video I have a 98 Sanoma I am going to do that today

[@BertitoPerez1]

Thank you for the video very helpful

[@myimplace7114]

Cool work.

[@nannynannou]

thank you! very helpful :)

[@billjohnson5951]

Great video, Mark I wonder why you disconnected the positive cable on the battery. Normally the negative (ground) cable would be the one to disconnect.

[@brentjorgensen5632]

thanks you saved my butt explaining the timing on the actuator the blue gear with the half moon. I have another actuator with a white gear and no half moon,,,any idea on timing this setup?

[@JeffMTX]

mad respect. well done

[@markbrad675]

Hey Bro,this is almost the same way I fixed it,we must be on the same wave length. The small wrench is called a ignition wrench,these are for working on steering columns and small nuts and bolts pertaining to the ignition system wiring and the mess under the dash and hood.Great job,looks like the same way I did it,a little different with the gluing if the gear,I used a epoxy from my job,and pull ties for the clamping,but I like you idea much better,much stronger.Fixed my blend air door also,it was blowing hot when on the coldest setting and my Mother-in law was bitching about it,so had to make her happy,as she is now,being her vehicle,and acting like I broke it because I work on cars,you should know about that crap.Good job,will subscribed to you,love your work,,Later my friend,keep up the great ideas and the fixes Bro...

[@ronlheureux7623]

I have a set of those tiny open/box end wrenches. I bought them at Sears in the 1960s. They are referred to as 'tune-up" wrenches because they're made for auto distributor work, like replacing the points, etc. They are really handy when working with small nuts in small places. Thanks for this video.

[@sandeew.544]

Awesome! The easiest is to just get a new one obviously- but that’s why we have a society of brain dead men now! It’s so much more rewarding to recycle- reuse and close the loop!! Lol seriously and it teaches you what to do when you can’t get to a store - no money, no part in stock, your on vacation, many reasons why you want to know w How to do things the long and right way!! Plus you learn why and how something important makes your car work! Thanks for sharing!

[@chriscanfield3664]

Another great vid. As a fellow owner of a 98 Blazer, I'm always excited to see what new vids you post. I attempted this repair last year, but see now how I screwed up the sync. I'll be taking another crack at it tonight.

[@jimrobcoyle]

Thank you. 1991 GMC 2500 This actuator is not available on Amazon or any where. I just fixed my original after the used one broke last week. Now, I'll put it in and fix the spare that just broke.

[@jimrobcoyle]

This actuator is not available on Amazon or any where. I just fixed my original after the used one broke last week. I'll fix it for a spare.

[@ramiromunoz4619]

great vid. Mark just wanted to as you if your blazer is a 4x4

[@Newtire]

I replaced a speedo gear like that with a tight fit like that one time and I had to heat it in water before i pressed it on. This, I discovered after breaking the first gear-I read the directions the second time.

[@Leo-cu1yq]

Thank you

[@noclu4u384]

Plastic shrinks when cold . Great design there GM .

[@AlexLatex2]

Excellent!

[@PreachTheGospel07]

Good job, I believe I have this problem. I have good cold a/c but I turn my heat on and it still blowing cold, not ice cold but cold. I believe my door is not opening because my radiator is full of antifreeze and both hoses going in and out of heater Cole is hot, so I think this is my issue. My next project, thanks for sharing your video.

[@1980bwc]

I bought a brand new one for $12 off ebay. Works great. Seems it would have been much easier for you to get a new one rather than going through all this time and trouble.

[@syllamo3887]

Used this method to fix mine and agree that it is a bad design as there is a constant pressure and it will break eventually - planned obsolescence? Thanks for the great video as I went to a junk yard and pulled 3 units which all were cracked but now I have fixed spares.

[@fahimhasnain]

Great.. Helpful

[@mitchk672]

Hi nice video, fixed my cracked gear like you did. I have another problem though. The vacuum actuator is connected to a nylon hook on the blazer you worked on. You actually hung the actuator to the side. Mine however is missing. It looks like some one broke the nylon tip off. What is the purpose of that vacuum part and will it hurt the vacuum actuator if I try to use it with that part broken?

[@phildevore4543]

Thanks, although I really don’t want to tackle this thing but I’ll do it anyway.

[@TheHowToCorrectly]

So the part you changed is only for the heat and cold air? So are the two blend doors vacuum things that are on the driver side changes the vents flow? (Foot well, to vents, to defrost) my problem is my air stopped being cold. and I see that it’s constantly blowing through my vents, I see a little difference when I change to defrost and foot wells. But mostly goes through the vents. It also blows alittle when I have the hvac controls turned off. also noticed if I’m going up a steep hill it will randomly blow colder air than usual. Or if I have it off it will blow warm air a little bit. What could that be

[@dippindotsarea3]

Thanks for the video, I've fallowed along with what you've done for my '99 Bravada. However, after I replaced the blend door actuator and re-installed the circular vacuum slave valve, but during the process the white plastic hook was brittle and broke a 1/4" from the connection hook. Is there any recommended way to repair that broken plastic point? It's difficult to work in that small space, I've already tried to use a jb weld 2-part epoxy but can't seem to get the angle right to have it bond in place. I'd rather not disassemble the dash further lol. Any recommendations are greatly appreciated.

[@johntaylor5526]

Great video. My actuator is OK, all the vac servos work. I assume the temp control selector is my problem. Do you have a video on Rn'R of the contoler i.e.: the easy way into the dash ;') JT

[@rocmiller3]

Thanks for the video. Is the vacuum cannister bolted in or does it snap in place? I not able to move it out of the way to get to the actuator

[@MrNopales1]

thanks!!!!!

[@condor5635]

Not sure what mine is doing but I think it is related. 2003 Suburban. Wife said air was only going out the windshield vents. I went out next day and started the Suburban and it worked fine. Several miles of driving and boom it all the sudden started doing it to me. The air switch was in the usual cabin vent position but air was coming out of the windshield vents. Moving the selector did nothing - air kept coming out of windshield vent. Any ideas? Would this be the actuator? Sounds like there might be two separate ones. Thanks for any help!

[@emmettturner9452]

The plastic/nylon swells as it ages which means a loosely keyed fit would never have split in the first place.

[@richv7095]

How do you replace the valve vent lever. I broke it replacing the actuator. I can't get the old on off to put the new one on. Thank you.

[@midixiewrecked7011]

5:30 for those of you wondering, JB weld in fact *Does Not* work on plastic., you need real glue for plastic.

[@clabough501]

I replaced the actuator in my 1998 blazer. Before we screwed the new actuator back in we plugged it in and it moved. Would that cause it to uncalibrate itself because now when I start it I have no heat even when I put to heat?

[@patrickdonohue9593]

Perfect just what I needed to trouble shoot and repair. Thank you great job

[@victorzamora9998]

I have a 2008 ford escape and keeps burning the door blend actuator any tips how to stop that?...it works for a couple of weeks only

[@mattward5444]

So glad for this video. Been trying to fix my actuator for a long time and tired of heat blowing in my face non stop. I tried to repair mine but it wouldn't calibrate so I bought a new actuator but still cant get it to calibrate right. Any help would be awesome..? Is the computer climate control bad?

[@JeffMTX]

gotta center the pot. see kzbin.info/www/bejne/aqizmGmrf6iBmdU

[@28tpi]

I have a 2000 GMC Sonoma and everytime I turn on the defrost I hear a clicking noise. I thought someone dropped something down the vent hole. I think it's probably that blend door actuator? Was yours making an annoying clicking sound too???

[@jtbatista]

Does this BLEND DOOR ACTUATOR the one in charge of blowing a/c on passenger side? my GMC ENVOY SLT 2002 has this heat blowing on the passenger side while driver side blows A/C (when I want a/c), yet my passenger side and back passenger side blow lukewarm air, or even heat.

[@LvisPazley1]

Nice video... My 98 Blazer- fan speeds work. Defrost, floor settings, etc all work... Problem is all hot air all the time.... Temp adjustment not working... Blend door, b.d. Actuator...??? Thanks.

[@jimrobcoyle]

Yep

[@markbinder352]

Does the heat control need to be on hot or cold when disassembly

[@peggygraham9170]

Can you please tell me where the blend door actuator would be located in a 1998 GMC Savana??

[@rlbadger1698]

Thank you for your video. I used 5 minute epoxy on the gear. Sanded out the gear to make it fit loose and give some room for the epoxy. I tried the gear set up, had to set the blue gear 2 teeth counter clockwise from what you show. Once again thank you for saving me $138.00. ps subed :)

[@rabughini]

hello. please can you tell me what is the R1 resistor value or line colors? Thank you very much

[@emmettturner9452]

The ones I’ve looked at are also missing teeth. The ones with bad motors are repairable if you have one with a cracked head you can salvage the motor from.

[@officerrobbins]

What symptoms did you have to determine it was the blender or actuator?

[@270.markham7]

will this fix the whining noise under the passenger side floor board

[@ducklandwikeno]

J B WELD DID WORK . ANYTHING BETTER .on ebay there a guy selling the replacement gear for these

[@cjeeperjohn]

Keep the awesome videos coming!!!. I got my actuator out and the gear isn't broke!. Any way to test the electric motor part of it or just assume it's bad and replace?. Again, GREAT videos. Your co-pilot deserves a good boy treat lol.

[@ducklandwikeno]

I also broke the white plastic piece on that big black part with the metal rod . I guess I need to glue it back .. but after I replaced my actuator didn't work right , no hot to cold still stuck on cold .also me I turn turn the metal part the actuator move back and keep doing that too

[@jamesferguson1054]

Come on guys, this much work for something that probably won’t work anyway. About $60 will get you a new one.

[@rosiegary]

Heres one for you My C68 hvac is stuck on the hot setting there are no codes no flashing lights both the head unit and the programmer were sent to bate.com for repair because of fault code had them refitted two months ago worked ok yesterday could not turn the heating down all the other functions work ie the blower speed heated rear window the only other thing i noticed was when i hold in the two fan speed buttons for five seconds to enter diagnostic mode to two zeros only how once i release the buttons were as before they came on when the buttons were held down could the problem be a cracked gear wheel in the actuator ?

[@louisgallaher5487]

mine has a split it blows out air between the air between the defrost and the vents

[@DavidMartinez-dl8lg]

Will this work on my 94 1500?

[@chilidog73]

If I wanted to just manually move the door to the correct position, can I just leave the actuator out or does it need to be plugged in? I have a 97 Aurora.

[@chilidog73]

+Mark Jenkins thanks. I could just move the actuator into the right position and then reinstall. I just wasn't sure if it Had to be installed for the others to work.

[@raterus]

In my case, I tried setting it manually, and the fan was so strong it stay where I put it. You definitely should try to lock it in place.

[@robertwomer9601]

Lot of work. Wonder if it lasted.

[@sotos2428]

Is that the cold and heat actuator

[@stelthcamo357]

Mine will recirculate air even know the button is pushed in in the light is on it won't recirculate could it be an actuator motor

[@kevenzavalavallejo958]

I have the same problem, how did you solve it?

[@ducklandwikeno]

my bolts on the actuator was 5.5 mm

[@JeffMTX]

yep

[@jamiesarkisian9769]

I think you can buy the part for $40. Looks like a lot of work to repair. Hope is lasts. I do not like to repair parts that require effort to get at. I like the way you glued and repaired it. In addition, I like to test it before I go thru the trouble of reinstalling.

[@jimrobcoyle]

My repairs are always better than the original weak design. That is the fun. Thanks, again.

[@mr.kingyosh4755]

did that make a hissing nosie?

[@mikenobbe1135]

they could make them easier to get to

[@kenhilson786]

I may be thick on this but is this the actuator for determining air temperature as opposed to where the air comes from (feet, dash windshield)

[@JeffMTX]

it switches between ac evap path and heater core path. the (feet, dash windshield) is on driver side, near gas pedal

[@adventureohio2]

S10 S-10

[@garyh7191]

Thank you Mark. It was the split gear. additional question is how do I replace the plastic spring that the vacuum actuator connects. It was worn and broken off. does it just lift off ? is it necessary for operation ? I see where the new spring and vacuum actuator comes as a set . www.amazon.com/dp/B0016IIZHU?psc=1

[@KatieHenry09]

My actuator is harder than that to remove-I’m stuck

[@willmacneill]

I tried doing the JB weld fix, but after a a few months the glued gear failed again. I found a replacement gear that worked really well on eBay: www.ebay.com/itm/GM-HVAC-Blend-Door-Actuator-Gear-Rebuild-kit-fits-many-GM-vehicles-1990-2013-/171384359235

[@alafrosty]

I've used JB weld on engine intake ports in the heads. That stuff will not suffer any breakdown due to heat cycles, even extreme heat cycles.

[@adamwithrow9785]

Why spend 4 days repairing the damaged gear when you can replace the entire assembly for like $40 and be done in an afternoon?

[@ldb5236]

Great video. Now for all the fat guys like me. You will cut the crap out of your hand doing this. Toughen up. Its worth it.

[@PopaZit]

You can buy a new gear for $11 on amazon

[@davetimms3723]

Just buy a new one. Advance auto parts sells the updated version and comes with a lifetime warranty, complete job 30 min.

[@Coyote.five.0]

verry nice video man but i think you can go to autozone and buy them for less than 15 us dollars

[@nannynannou]

the actuator or the gear? the actuator we needed was $150

[@justinstandifer604]

@@nannynannou I just buy a cheap no name $15 actuator off eBay, then transfer the gears over to my original factory actuator. Those $15 actuators only last two years before the electronics fail, so use those for parts only.

[@MrIsntOnAGen]

This turned out to be the wrong actuator for me

[@juancontre5858]

Too much work better to buy a new one less to worry about it taking it off again just saying