GMC Sierra: Stuck On Defrost

[@SouthMainAuto]

Guess I failed to mention in the video that customer had all ready purchased a new OEM actuator. Just to be sure I wasn't crazy I tried it but knew it wasn't gonna work from our test results. He told me to just leave it in because he already bought it. 🤷‍♂️

[@jdrs4214]

Now that’s what you call a Vehicle Air Conditioning System Crash.

[@johnjames432]

Had a focus that a blend door seal was all so the problem after it was warm stick like glue 🤣

[@boforgault3212]

Hack Mechanic my arse. You are the Sherlock Homes of the Auto World

[@The_Redkween]

I’d lay down a $400 bet that the owner will not want to tear into the heater box. I know I wouldn’t. 😂

[@manorin]

27:04 MFG March 30 2020

[@jackrichiedei]

I remember when it was cable operated and never went bad. slide the lever left for floor, middle for vents ,right for defrost.

[@buckhorncortez]

I remember when gas was 23 cents a gallon. What's you're point...?

[@john7017]

@@buckhorncortez And I remember when people were courteous to each other...

[@antonoudenhoven7573]

@@john7017 best reply to a troll,well spoken sir

[@valvemonky4734]

@@buckhorncortez what's yours ..?

[@Jihadbearzwithgunz]

I had a cable break but it was a easy fix. Even the old vacuum driven systems were easy to fix if it's not working more then likely a vac leak cause the vacuum systems themselves rarely failed. If they did it was they sat for too long and we're stuck easy fix.

[@gregsimon1285]

Every once in a while I find a channel that I like so much I start binge watching it’s old videos. Yours is one of those. You mix education, practicality and a dry sense of humor to make a very entertaining product. Thanks for what you do.

[@rons4452]

That is only in the first 50 videos LOL

[@gfd1166]

i was doing just that today... cued up the CHEVROLET list & let 'em play. Made it through 30 of 'em.

[@QBRX]

Yeah, he's absolutely the best!

[@Sprnklrmn]

Yep. Me too. My kids are sick of it. 😆

[@1musicsearcher]

Figuring out that the arm was traveling too far from the remnants of foam laying around proves you’re a genius!

[@MikeBrown-ii3pt]

"Back in the day"...when the "HVAC" system position was controlled mechanically by a sliding lever and a wire, these problems were few and far between. Thank God for progress (he types with a whole lot of sarcasm)!

[@MikeBrown-ii3pt]

@John Stone Rookie hell! I'm 52 years old and have been working on everything from lawn mowers to semi tractors since I was 8. I'm calling bs on you!

[@russdavis1960]

@John Stone troll

[@MikeBrown-ii3pt]

@John Stone You have a right to voice you're opinion and I'll always support that right...even when your opinion is wrong! Have a good night.

[@rons4452]

Back in the day there was no youtube So who was or is better off ?????

[@christhomas9016]

Guess the days of cracking a wing are gone too..

[@stevewesley8187]

Just shows electronc theory knowledge is necessary , but so is theory of mechanical functions ! Good job !

[@Asto508]

Ye, being able to read schematics and have a basic understanding of circuits is a minimum today. Not much is required beyond that though because if electronic breaks, you can only replace it as a whole. I doubt that Eric would go into soldering broken resistors and capacitors simply because of warranty.

[@WatchWesWork]

Very interesting! I had the opposite happen with an old GMC truck. The blend door had warped and would never reach the full 5V position. If you put it at full hot it would continuously fight the warped door and eventually burned out the actuator motor. I also gave the customer two options: Tear apart the dash and heater box to replace the blend door, or take a small file and turn the squarish drive slot in the actuator into more of an hour glass shape. You can guess which option they chose!

[@edwinpadilla6093]

WOW I got the same problem it doesn't reach five !

[@samcripes3046]

That's great to know! I'd never thought of that or seen it!

[@franksgarage8551]

Had a similar problem. Took actuator apart and moved internals so door bottoms before the potentiometer tops out. “Manually calibrated” Foam missing, time for a colonoscopy!

[@valkokir]

Do customers appreciate what an amazing mechanic you are? I can't imagine most people figuring this one out without a huge bill for parts not needed. You're awesome.

[@mariosaccoccio1688]

"You can't go to war until you know what you're fighting!" Every married man knows that!

[@yqwgjsg]

Yes and worst food for a man to eat...... is wedding cake.

[@christopherj9494]

Ha ha "That's the Main Thing" Get this thing working..."Like a Rock" Priceless Great Work!

[@mshafer2006]

Not a hack job by any stretch IMO, I call it re-engineering to save the customer money and time without the vehicle. I wish I could do that sometimes. I can’t as a warranty only technician.

[@trevorkosolofski8976]

My thoughts exactly! This is by no means a hack job. It’s a simple long lasting solution to a very expensive repair.

[@thesearcherman6652]

Michael Shafer- What does a warranty only technician do for money? How do you live without money? Auto manufactures sure as hell ain’t going to pay even minimum wage to fix their cars.

[@MattAlthouse]

I’ve been living with this problem for two summers. Now it’s fixed. I could give you a hug.

[@JCHD18CVOLim]

The first thing I noticed was what looked like "popcorn" under the dash and on top of the dash. Who would have "thunk it" that was the root of the problem. Great Video Eric.

[@brianthompson2045]

I am shocked this channel is not over 1 million subscribers. Great job!

[@robgrasso947]

I cannot express how thankful I am to have come across this video. Mine has been like this for about a year. I tinkered with a few things before looking on KZbin. I followed along and was able to do the same fix. Everything works as should now. Thank you so much for taking the time to help others out.

[@GeoffPerkins-c9i]

Ar first I thought this video was ridiculously long for the topic, but you went into detail on stuff I haven't even seen brought up in many other videos. I'm working on a Cadillac ATS but your explanation helped me figure out that I had over clocked the actuator when trying to like it up and cause my problem. Thank you so much for the time and effort you put into this!

[@Burgie_productions]

Have you tried the blend door relearn procedure… sometimes the actuators get all out of whack and you have to pull the fuse for 1-2 beers (10 minutes or so)😂 Replace fuse and then let the module “re learn” the actuator positions. Don’t touch the head unit buttons or dials when all this is happening, it will cycle through all blend door positions on its own and recalibrate the blend door actuators

[@pirtatejoe]

Yes to this comment. My brother's Blazer of this era had this problem. Ran though all sorts of troubleshooting until finally stumbled on the blend door calibration procedure. Know knowing about it, should have definitely tried that first. From what Eric was saying, I wonder if the recalibration procedure info wasn't in the service data. It seems like one of those little secrets people either know about or don't.

[@timsmith4109]

Just a couple of quick questions Burgie: When you pull the fuse, should the ignition be on or off? During the relearn, should the HVAC system be off (fan off) or some other position? Thanks

[@dougkubash8673]

Great video Eric! I just retired today - 42+ years wrenching. I will be lost without the 'theory and operation' section in the service manuals, lost access to the service manuals when I retired. On this problem it wasn't enough information. Great fix!! I own a 2012 Sierra so if this problem happens on mine it is getting the 'screw fix' Keep the videos coming!

[@tedchristman164]

You can Hack any of my rigs any day!

[@dennisgundlach87]

Thanks for having us back, South Main Auto, always welcome in this house

[@ColdStartAuto]

Ooooh! I know this solution even before you start. Wish you woulda made it before it took me 3 hours to figure it out. Fun fact!! The part numbers between the mode, blend, and third door (or auto air trucks) actuators are interchangeable, as in they fit and plug in perfectly, but are NOT the same part. It will cause it to act strangely. In my case, the mode door will act backwards. (Air on defroster when on vents, vise versa) Also. When diagnosing do not plug the new actuators in when not installed to “test.” They will work, but can move farther than they’re supposed to when installed and they will ruin themselves. I know all of this because I personally did all of this a few times.

[@jackfentress0281]

So what did you do. I have the same problem as you did

[@ColdStartAuto]

@@jackfentress0281 edit: wrong reply If you’re having them work backwards you have the wrong acuator in the wrong place. The blend door will not work in the mode door spot, even though the look exactly the same and plug in. If you over extended the actuator you can try to get it back with a 9V battery, but normally they are ruined. Good luck.

[@132isaac]

@@ColdStartAuto how do you move with 9v battery?

[@ColdStartAuto]

@@132isaac you use two wires coming off the 9v, and touch them to the posts on the actuator to get it to move side to side. If you locked it all the way to one side it’s already toast tho

[@brandondvorak4438]

@@ColdStartAuto on my 2002 I replaced with a doorman. I hooked it up prior to install. It moved quite a bit. Then read ur supposed to put them in first before powering. So I took cover off and lifted the one gear up and then repositioned the marks like they were before and put Gear back down and cover back on and installed it. Worked great for a few times then quit. Could it be doorman are trash lol?

[@ApexHotShot]

Eric, this diagnosis and solution, for me, validates your diagnostic technique. By following those proven steps you verified that the usual suspects were Not the problem and that led to creative / outside-the-box thinking … eventually resulting in a leap from blend door foam fuzz to an extended run on the defrost actuator. Absolutely brilliant!

[@ShallowGraves01]

You are a genius. Trailblazers have the same issue. A person could spend a lot of money and many shops would never figure it out the way you did. Simply amazed. You are awesome.

[@andrewrae2813]

the old cable controlled system was a lot less headache. another good video, tnx

[@Quazi1966]

Sometime needs must. I purchased a door actuator fo a Hyundry to find that the worm gear on the motor gear was a lefthanded one instead of a righthanded one. I just swapped the polarity of the motor supply and it wound the gear the other way, worked a treat! You did an appropriate fix under the circumstances surrounding the problm and the vehicle.

[@jwark6]

in 2016 when I worked at a Chrysler dealership we had a service bulletin to re-flash the BCM in many Jeeps because the foam that sealed the blend door to the box would get smushed and collapse over time causing the actuators to go past a programmed "limit". The flash just increased the voltage limit the computer would allow as acceptable.

[@markh.6687]

Some Fords have similar issues; Dorman makes a blend door repair kit that doesn't require removing the whole dash to fix the failed foam issue.

[@notsureigaf]

I can't believe GM and Chrysler engineers never considered that this could happen and program some sort of fail-safe other than "stop working entirely." Actually yes I can believe it.

[@markh.6687]

@@notsureigaf Or design it right and eliminate the failure point entirely.

[@notsureigaf]

@@markh.6687 That kind of thinking is what brings on failures like this in the first place. You should always have a backup plan or fail-safe even if you're sure you designed something right, so that if you end up being wrong about your design, at least some poor schmuck doesn't have their HVAC stuck on defrost.

[@MrGHOSTMAXX]

This is very insteresting, I always wondered why some models of Jeeps always had blend doors breaking. I guess they go past their limit like you mentioned, and break the door or shaft. I've even seen a Jeep with a upgraded aluminum all blend door snap the door right off the shaft.

[@RickTrajan]

Her: "he must be thinking of other girls." Him: "how do I fix that damn truck?"

[@kawasas]

Hi Eric O. Lots KZbin are saying that need power reset by taking fuse out.

[@randymarion2466]

If it is not that 'Damn Truck', it has to be 'Where's the nearest ice cream?'

[@SouthMainAuto]

@@kawasas not this style. I double checked. It's the latter models.

[@johnnyheckard7185]

@@SouthMainAuto Yeah the old battery cable or fuse pull to perform a reset or relearn on these usually only temporary they will do it again and again until you fix what it’s fussing about.

[@scottboyne8305]

I can't believe I'm 57 years old and I binge watch your videos all the time. You are an excellent mechanic, and you're funny too. And I like when mrs O makes an appearance. Very entertaining

[@kevinreigle8282]

you go above and beyond what most mechanics would ever do,, ABSOLUTLY FANTASTIC,, if you would not of done what you did that costumer would never had his heater control back,, YOU SIR are the BEST

[@Drei959]

Thank you so much! I’ve replaced plenty of blend door actuators on my truck. But for mode door I was so confused why it was getting stuck at defrost with a brand new actuator. I knew my control module was good. So I put a screw exactly where you showed and now it works perfectly!

[@TheMetallicafan88]

working on southern vehicles is always a treat!

[@dlewis9760]

Might not need to defrost the window, but the foam (if that's what it is, don't know unless you rip it apart) isn't going to be a climate thing, it's going to be a age thing.

[@biz4twobiz463]

West... west are the best! haha

[@61rampy65]

Southwestern vehicles all have extremely brittle plastic pieces and rubber parts. Gotta be extra careful to not break stuff.

[@tysshed5807]

@@dlewis9760 the heat and dry air dose kill plastic parts even here in Missouri the summer heat murders dashes and interior bits. But in the north east the salt eats the cars so it's a give and take

[@christiaanbrown4278]

My truck-no rust, no plastic (lives in Arizona). All my plastic is so brittle that a good bump will send pieces of the dash to the floor.

[@timsigers3327]

This happened to my old Silverado today. I opened the little motor, and observed what you observed on your meter; if you put the knob all the way to defrost, the little motor would not stop spinning. I probably would not have come to the conclusion that the foam had deteriorated, allowing for over-travel. I watch all your videos, and just happened upon this one by chance. I appreciate you taking the time to teach the rest of us, and making it entertaining in the process!

[@lawrencetickle2706]

Man I was just thinking, "It would be nice to have a new SMA video tonight."

[@labradormcgraw]

Strange... I wasn't.

[@lawrencetickle2706]

You're right.

[@Dirtyharry70585]

Yeah, Ivan has two videos before Eric. Must be the NY snow.

[@-BuddyGuy]

I was thinking it's time to sleep or I'll be exhausted tomorrow. Fuck

[@rons4452]

Guess what? Your girlfriend was not thinking the same thing LOL

[@danparker1925]

SMA to the rescue!! I spent so many hours trying to install this. I thought I was clocking it out of time and couldn’t get it to go back to panel. I installed the screw in the cog wheel as per your instructions and wow, it’s perfect. Thank you so much

[@hankhessig6586]

Ouch - I certainly wouldn't have suspected the loss of the sealing foam would lead to the mechanism not working. Good lesson for sure

[@NRCustom]

My buddy's plow truck has this exact problem. Sending him this video, he'll be very happy.

[@rhinogear]

THANK YOU! Watching the actuator operate, seeing WHERE the panel position is and defrost position is under the dash on that wheel makes ALL the difference! Also knowing what position to have the switch in and where to set the gear under the dash. Thank you! Love the channel~

[@mrmtdew2001]

Nice job, this was the exact same issue I am having on my 1999 GMC with 300,000. I appreciate the detail. I was able to make the same “type” of repair with the new stop for the defroster lever. Thank you.

[@noeygarza64]

Back in the early days, we just make sure your vacuum line was connected.

[@timsmith4109]

OMG what an outstanding video South Main!! I have been fighting the same problem with my 2001 GMC for months! It goes to defrost and won't return. I am on my third OEM actuator and have pulled out a lot of gray hair trying to figure this out. I was at my wits end when I found your video. I did confirm that the original actuator was bad as it wouldn't move at all installed or removed and slaved in. I am going to install a screw in the defrost door track and see if the foam is the problem, although I don't have any extra foam floating around the truck like you did. Thanks a million and I will update my findings.

[@brianjohnson5144]

I'm proud of my self I kept saying put a screw in it and you came up with the same repair. I really enjoy your videos

[@sarahdeshay1394]

I early on suspected that the door was moving to far and a stop screw would remedy it.

[@johng1077]

Yeah when I hear South Main Auto I always think south main hack repair...you are too funny Eric O can’t imagine anybody saying anything bad about that fix, you are keeping your customer in mind trying to save them some $$$$$ anybody else would of replaced everything! Great video as usual.

[@fevengr9245]

Eric: As a retired engineer, I’m embarrassed that someone in my profession would design a system to fail in such an obscure way through nothing more than ordinary wear and tear. But good on you for going the extra mile to figure it out! I’m sorry you had to go through this. I imagine that GM considers an HVAC system design that fails as the foam disintegrates to be a “feature”.

[@lance1097]

This video confirmed my suspicion of the door over extending . They put a new motor and control head already. Exact same problem. Thumbs up.

[@Alpha-zulu-009]

I am amazed at your logical diagnostic process. I was a service manager at a GM dealer for 13 years and I doubt any of my techs would have found this without just replacing all the external parts. Well done sir!

[@afterhoursfab]

Just had a high mileage 2006 Silverado in for the same problem: vents stuck on defrost. I found this video and said "well hell, this looks like a cheap fix!" It was not. During testing I was getting all kinds of wild voltages at the actuator, and after confirming the wire harness was ok, I decided the control panel was the problem. Installed new Dorman part, programmed it to the correct vehicle, and everything was working again. Thanks for explaining how it all worked though 👍

[@randymarion2466]

I just knew you were going to go full 'Ivan' on this!!! Nice job, way to go!

[@rons4452]

Who is Ivan ??

[@tysshed5807]

@@rons4452 garage 51 I believe is the KZbin channel it's a Russian mechanic that dose all kinds of stuff to old shitboxes mostly for entertainment

[@randymarion2466]

@@rons4452 Ivan of Pine Hollow Diagnostics ... A young man yes of Russian heritage, but a genius in diagnostics and repair ... He often will take something that is broken and take it apart and figure out how to fix it.... Sometimes his repairs are a bit out of the box, like this one from Eric at SMA. Check out his channel... You won't be disappointed

[@SpringfieldSheriff]

This is the best description repair out there for this issue I’ve had several vehicles come in my shop with this issue and this video has saved me several times.

[@weshawkins7165]

Love your videos Eric. The thought process that you use and describe as your doing the repairs is as valuable as showing the work. Good job.

[@gkin20]

I had a two part problem as the actuator had a split plastic gear inside and would do nothing. I replaced it but low and behold it would stick in defrost after going through the motions. I watch all the time and searched your videos and came across this one. Guess what? That awesome screw mod worked wonders! Good enough for me seeing it's an 2003 gmc. Funny thing, I've never had to do anything to our tacoma or tundra. 😀 Thanks for all you do from being a great service to your community and bringing us these very helpful video's. I didn't even use my big fancy scan tool! 😜

[@topcat5777]

I am beyond impressed with your diagnostic skills; thank-you very much for making and posting all the videos you have done! I wish I was 1/10th skilled in understanding electrical schematics...and knowing what appropriate tools to use and how to use them relating to electrical components. But then again, that's what trade schools are for and taking the theory and putting it into action. Be well and be blessed.

[@tourswag8616]

Nice work. I live in AZ and my 2001 Sierra experienced actuator problems- this video showed me a couple things including the possibility ( probability) that rotted foam was jamming the works. ( was stuck on defrost) You methodical examination well explained how the system works and is controlled. All sorted out and have good control of all 3 actuators. Thanks.

[@LFBsmokealarm]

Just got into bed here in UK and an SMA video comes live. Ah, perfect timing.

[@jacknasty6940]

Cheers mate

[@connomar55]

Need to move over to USA like I did lol!

[@rons4452]

You know that sounded KINKY!!!

[@LFBsmokealarm]

@@rons4452 Upon reflection I could have worded that better! 🤔

[@rons4452]

@@LFBsmokealarm Ha Ha Ha Too funny!!!!

[@usethenoodle]

You are one sharp diagnostician. Rotted foam on the blend doors. Amazing!

[@alward9901]

Ivan would be proud . Almost a Russian fix. Great fix and diagnose Eric

[@markh.6687]

In Mother Russia, heater control pins YOU!!

[@reecenewton3097]

@@markh.6687 In old time Mutha Russia, got no heater control, no heater, no truck, just Gulag.

[@ronallen6578]

Eric, I have this trucks 1/2 brother from another motha. Within 1000 miles and its an 02. Gives me something definite to look for. Only difference is I've never seen any of the foam anywhere. Here I go, but at least I'm armed with a boat load of wisdom from Eric O. Thanks a ton, Ron

[@antonoudenhoven7573]

Am i the only one that give a like before watching the video Greetings from a big fan from the Netherlands

[@javierferrer8598]

I give him a like before the videos on all the videos because I know they're all good 👍👍

[@unclemarksdiyauto]

Yep Anton, you know Mr O's video is gonna be a good one, even before we see it. He is a good tech/mech & teacher!

[@rons4452]

AWWWW no little red heart for you!!!

[@antonoudenhoven7573]

@@rons4452 shame lol. Can't sleep now hahaha. Can't get it all

[@Cheepchipsable]

Shows you are undiscerning.

[@davidmcclain5180]

I live in the Phoenix metro area and if this customer lives in the hot area of Arizona (not Flagstaff), the heat we have will destroy the foam and it comes out in pieces as you observed. Great diagnosis and following your procedures kept you on the right track. Also being persistent is the thing that pays off. Many times I've wanted to give up but if you keep thinking and testing, most of the time you'll find the answer.

[@AntonioClaudioMichael]

Nice find Eric O interesting the foam being blown out caused it to hyper extend and the potentiometer didn't like it nice repair with a screw @SouthMainAutoRepairLLC

[@cbro6535]

These are by far my favorite model of GM trucks so easy to work on and the last forever if taken care of and the rust doesn’t eat them alive

[@rodneymiddleton9624]

The last one that came in the shop all 3 motors were bad, mode, blend and recirc. The recirc motor was the worst to change. The customer brought me all Dorman components. Needless to say they were all junk and worked a couple times before they failed. I ordered ACDelco components and worked like a champ! Thanks Eric O!!

[@Mintman70]

Great fix for an old horse to keep her working. Most shops would have sold them the entire ranch which would have fixed the problem at a much inflated cost. Thanks for restoring our faith in honest repair shops. Please relocate to Long Island, we could use a shop like yours.

[@steveb6103]

It's a whole different world down south. Instead of salt it's the heat that rots anything plastic.

[@ctbale1]

And rubber!

[@cward1954]

Turns plastic into a brittle mess.

[@SunCityOffroadRecovery]

Heat. sand and lack of humidity here in El Paso... lately we been getting a ton of rain tho but everything is already rotten lol

[@williamclintonjr.5508]

Your not a hack mechanic,your a true mechanic not just a parts changer.Most of the so called mechanics would have just started throwing parts at it and charged the customer and said I don’t know what’s wrong with it,great job

[@johngrabinski4873]

your the only mechanic in the world who would have figured that out quickly without throwing parts at it

[@user-fm6ny3uo2b]

Sorry John, good mechanics all work this way. Logically and using the proper diagnostic approach will get you to a solid conclusion almost every time.

[@bm20091]

Dude, bro!!! Man... I'm at a loss for words. I LIVE, ON KZbin! [Yeah, it's lonely.] But I've watched a looooot of videos...from education, entertainment, art...And I believe this is the BEST educational/informative video I've ever viewed! Your play on words and casual tone, explaining circuits and currents, and how it all operates, is beyond compatability for the common person. Not quite sure if this will work for myself, or not, but glad I viewed it either way. Thanks a ton!

[@jimpie231]

A work around! Welcome to Today’s world! Jim PS.....GREAT JOB!

[@troymurphy6471]

You saved me a ton of aggravation, mine had the exact same problem. Thanks keep up the good work.

[@javierferrer8598]

Good work I bet he keeps it like that since this old truck and it costs an arm and a leg to take a dash out 👍👍

[@mr.rickisinthemixxx9676]

I've been searching & searching for many possible scenarios... I am glad that I stumbled across your channel. Your attention to detail & clear explanations, have helped me identify different options for solutions to the same issue I'm having. Many thank yous

[@hpelisr]

That 200,000 miles was just getting to Eric's shop. Nice work Eric, I need to look at my S-10 it is doing the same. Thanks I heard that comment about being a Hack.

[@TheMechanicj]

It’s the vacuum line going to the drivers side fender urs is not electric it’s vacuum operates I’ve repaired hundreds of those line s

[@hpelisr]

@@TheMechanicj yes I did have a problems with that. I will have check again. Thanks

[@David1pearl]

Yeah it is a fun time to find that port let only push a tube on It. Hope you are good working with a mirror.

[@WreckDiver99]

22 Year old Tahoe here...in Michigan...Still running, and unfortunately has lived outside for the past 15 or so years. Having HVAC issues as well. Looks like I'm in for a a new blower (squeals like the guy from Deliverance), and new resistor (I have two speeds, OFF and balls out). I will say that my doors move SUPER slow or get stuck. Once in a while you get "THUNK" when it figures out to change the door location. This is a good video for future fixes.

[@jeffreybegeman9544]

I thought I was watching Vice Grip Garage with the "Well I'll be dipped" quip.

[@michaellong6695]

I want to thank you for such a great review of this issue. I have been trouble shooting this same issue on a 2002 2500HD for a month. I replaced the actuator for the same failure and had no change. Still stuck when switched to defrost. After watching your video, I went back and checked signal voltage again with the same 5v shut off at defrost. Added the screw to motor housing and it works perfect. Who would have thought that foam seal could cause this much of a problem. Thanks again.

[@davidarnette327]

Me-maw would be proud!

[@wirenutjoe]

Nice! Who would have thought of missing foam. Glad thing you had some missing foam laying close the area to give a clue. Great job

[@fascistpedant758]

It would have been interesting to try a small resistor across the ground and signal to keep the voltage below 5V. I may have done a similar hack on a TDI or two to limit travel when the manifold runner control linkage wears a little. Sure beats a new intake manifold from the dealer.

[@brianmiskell9090]

Ran into a very similar issue and the passenger compartment filter was never changed and the air flow was keeping the actuator from moving it's full sweep. Good stuff man. Enjoy the hell out of the gm videos as I have the pleasure on working on that crap everyday

[@specgrade3275]

I wanna go back to the days of levers and cables. None of this electronic bs.

[@christhomas9016]

Remember when blend door meant each down on the outer kick panel and pull the handle had way back, and all that cowl air got your ankles and shins?

[@forkintherode8236]

You are a true sleuth. What impressed me the most is when you said I thought about it last night. Excellent

[@MegaDysart]

I'll be dipped! Someone's been watching vice grip garage

[@jayneville1]

This video saved the day for me. Had a k3500 farm truck with 300k on the odometer in the shop with the exact same issue. (Foam on the floor and all...)Tested by flow chart and everything checked out... Tried a used panel, still no return from defrost. Going in to work this morning and put a screw in that new OEM actuator I hung on it yesterday morning. Thanks for all you do. You just got a new subscriber that will be sharing your work with others in the field.

[@IgorD33]

If nothing broke we would not have SMA videos

[@patrickherbert1018]

Thanks for such great insight into tracking down a problem and finding a solution that won't break a person's bank

[@korton3665]

I work at Chevrolet dealership 7 years ago we started having the same problem

[@rons4452]

How do you like working on foreign cars?

[@saltcar]

Impressed with the logical approach and analysis of this. You just don't get this at most shops, dealers included. Nice job. Keep it up!

[@sanctealphonse4510]

Can't believe you're only at half a mil subscribers. Figured you'd have Kilmer, Eric the car guy and Chris Fix dying to do collabs with you so they'd get more popular.

[@RedCan_Rick]

Your screw-stop hack worked in my situation. New actuator, would stick on defrost. I thought I was calibrating the doors wrong. Thank you for the great tip!

[@kevinbarry71]

After all those years in Arizona; it probably never use the defrost before. Welcome to winter

[@richardbambenek2601]

The Arizona heat destroys cars, not by rust but by rot.

[@kevinbarry71]

@@richardbambenek2601 yes it does. But still better than rust

[@charlesmares4143]

Good stuff! I appreciate that you showed the position and movement of the actuator. That’s currently what I’m replacing. Thanks!

[@AntonioClaudioMichael]

That is interesting its like there is a problem with the electrical that is causing the actuator to get stuck Eric O @SouthMainAutoRepairLLC

[@BryanAnderson-rl6uq]

I got the same truck and problem. I appreciate the light you just shed on that problem.

[@davidhinkle2207]

Could the lack of foam on the doors be causing the lack of air flow

[@Gabriel-unicorn]

Great diagnosis and preservance, i would have thrown an actuator at it, but the clue of the thumb holding the actuator and then realizing the foam was your thumb, really helped. Thanks again, I'm doing the same tomorrow with my 05 Yukon rear heat door.

[@Gabriel-unicorn]

Just finished the work. Tested the door position voltage and of course it was 5V. Added two stop screws, screwed directly into the plastic actuator case which kept the main actuator gear from over rotating, (like Eric's thumb). Recalibrated the actuators (remove battery voltage for 1 min then reconnect, start car and wait 2 minutes for the self calibration). Door position voltage now 1.2 to 4.2 volts. $0 repair. Thanks Erik for inspiring me.

[@paulog8813]

Great diagnosis. I hope I had a true mechanic like you nearby. Let me ask you. Is moving to Rio de Janeiro, Brazil ou of the question? 🤔

[@SouthMainAuto]

😂👍

[@darrylhowe1465]

Above and WAY beyond. I would like to extend my appreciation to the depth of effort and expertise you apply to these difficult diagnosis.

[@ryguy57106]

Get the parts cannon out!! You’ll eventually get it 😁

[@markh.6687]

"I can rig a stop for the circuit, but she won't last fer lang! I canna be responsible for th' safety of the dashboard, Jim!"

[@SuperBigdanno]

Good for you Eric for saving the customer money! Refreshing to see

[@dlewis9760]

30+ years from now, the old car hobby is never going to include cars of the last 20+ years and probably not the future. It's the plastics that are going to send cars permanently to the bone yards. Instead of the term "Rust never sleeps" it's "Neither does synthetic foam and plastics degradation". Being a southern car isn't going to save them either.

[@fascistpedant758]

ICE cars are better now than they've ever been and probably won't get much better as electric cars will be taking over. 30 years from now people will be fighting over today's cars.

[@Mattvardaman]

I have this same truck and same mode door problem. If I climb under the dash and help it off defrost then it works great, if it ever goes completely to defrost then it’s stuck again. I refused to buy a motor to replace one that’s working, glad you figured it out for me! I’ll take it apart one day this week