GMC Sierra: Stuck On Defrost

In this video I have a look at an older GMC Sierra that had a customer complaint of the HVAC being stuck on defrost. My gut told me "prolly just a bad actuator." However, the data showed us something different.
If an SMA Video has helped you out please consider giving using "Patreon" to help support us. The videos take real time to create and pull us away from real work that pays our bills. CLICK HERE: / southmainauto
CHECK OUT OUR "SMA SWAG" STORE! Go on Teespring and get your very own SMA merch!
teespring.com/...
If you don't like Patreon feel free to use the "PayPal Me" link: www.paypal.me/...
The South Main Auto Amazon Store:
www.amazon.com...
AES Wave Automotive Diagnostic Tools: www.aeswave.co...
Thank you for all the continuing support!
--Eric & Vanessa O.
Feel like sending some swag to SMA because you love the videos but don't know where to send it?
Just ship it here:
South Main Auto Repair
47 S. Main St
PO Box 471
Avoca, NY 14809
Disclaimer:
Due to factors beyond the control of South Main Auto Repair, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. South Main Auto Repair assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. South Main Auto Repair recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of South Main Auto Repair, no information contained in this video shall create any express 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 the information contained.

[@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. 😆

[@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!

[@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.

[@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.

[@1musicsearcher]

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

[@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!

[@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.

[@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.

[@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.

[@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?

[@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.

[@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..

[@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.

[@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.

[@noeygarza6522]

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

[@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.

[@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.

[@autotek7930]

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

[@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!!

[@lackeydehackey405]

The Avoca rodents ate his foam. I wonder if a 5.0V Zener would clamp that signal at 5. The electrical way of the screw. Keeps it from going over 5.

[@lwilton]

If I recall standard Zener voltages were 4.7 and 5.1. The screw fix is probably a better solution.

[@michaelpolimer2128]

@@lwilton if you put in a 4.7v zener to clamp the voltage, when the zener started to "zener" it would draw a lot of current (limited by the controller, maybe) and possibly over stress the source or the portion of the pot above the wiper. the screw was an elegant solution. I figured Eric would epoxy in the nozzle from a can of Brake Clean!

[@lackeydehackey405]

@@lwilton NZX5V1B would do

[@sparcnut]

I would have instead ohmed across the pot (i.e. tested the resistance between the actuator's ground and 5v reference pins), then added an appropriate value resistor in series with the actuator's 5v reference pin. For example, if the pot was 10K I'd bet that adding 220-470 ohms in series with the actuator's 5v reference pin would do the trick. This basically adds a bit of fake unreachable "range" to the 5v end of the pot's resistive track without any undesirable loading effects. The pot is clearly just being used as a simple voltage divider, and this sort of minor addition to the pot's overall resistance is not going to bother the controller at all. The pot itself probably has a wider tolerance rating than adding 470 ohms to a 10K pot would introduce (+4.7%) anyway - it's probably only a 20% tolerance part to begin with!

[@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.

[@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

[@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.

[@dennisgundlach87]

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

[@kittty2005]

Old? He's got another 200,000 to put on it, I had 320,567 on mine it would have continued if the salt cancer hadn't taken the gas tank and pickup bed ,other than that the truck ran fine.

[@stoneblue1795]

"I'll be dipped"..... Copyright Vice Grip Garage. : )

[@HOBrian2003]

I guess we know Eric watches Derek!

[@goodfellasinc.5648]

Vgg did not come up with that my Grandpa's been saying that since world war II lol not only that this guy will run circles around Derek we should all have a build off nobody wants to participate anymore in a friendly build off

[@halleffect1]

@@goodfellasinc.5648 Eric is frigging awesome but don't sell Derek short. he's a very good mech

[@dlewis9760]

"The Beans" - Sarah -n- Tuned

[@mikeybhoutex]

@@halleffect1 Indeed, his recent three parter for the engine build of Independence is good stuff indeed! Also, the block turned out fantastic, can't wait to see it run!

[@andrewrae2813]

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

[@davidarnette327]

Me-maw would be proud!

[@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.

[@marksmith6104]

If a serial criminal was being investigated by Detective O, we all know how that’d end.

[@rons4452]

Yea by subscribing and commenting!!!

[@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

[@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”.

[@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?

[@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.

[@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

[@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!

[@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

[@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!

[@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]

😂👍

[@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.

[@brianthompson2045]

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

[@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.

[@rguy2684]

Extremely dry atmosphere in Arizona, destroys all plastics including the cheap foam GM puts in their vehicles!

[@rguy2684]

@John Stone okay genius, maybe you need to explain it to everyone. Let us all know how the desert isn’t dry.🙄🤪

[@rguy2684]

@John Stone didn’t you comment “false”? So I’m wrong about that as well. I’m no rookie by the way, seems to be offensive.

[@aday1637]

You mean the cheap foam China puts into GM's vehicles. That witch that took over GM is now getting everything built over in that God-forsaken place. They hat our guts and purposely make everything crappy.

[@TheBigChinoDon]

AZ resident here and I just did my blend doors in my Dodge. It's not dry atmosphere, it's time and UV. As that truck is 20+, the cheap foam just broke down from age. UV can't get under the dash.

[@rguy2684]

@@TheBigChinoDon so, ummmm... you are mostly wrong. It is a very dry atmosphere and the fact that the atmosphere is dry pulls the oils out of everything. UV does destroy plastic much faster but the dry air makes the plastic brittle. Foam will fall apart faster in dry climates the in climates with higher humidity. Your explanation doesn’t explain why plastics fall apart there faster then in Georgia. Sun is the same distance yet plastic lasts for longer.🤔🤔

[@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.

[@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

[@IgorD33]

If nothing broke we would not have SMA videos

[@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~

[@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.

[@johnaclark1]

Is it not possible there is supposed to be a stop of some kind inside or on the actuator itself? I've seen some of these with a cam on the outside that physically stops the actuator from going more than roughly 180 degrees of travel.

[@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.

[@pv2xeek]

The best thing you could do for this customer is disable that "Auto 4WD" button on the dash. Otherwise you'll be putting a transfer case or front diff in it for him before it's over too. One of the worst ideas GM ever had. "Hey let's engineer a 4wd system that waits till the rear tires are spinning and then just suddenly engages the front diff to either shoot the vehicle out into oncoming traffic or explode the drivetrain because the front tires were on dry pavement but the back ones weren't." "That's a great idea Bob. You deserve a promotion."

[@loggingdaddy]

Forgot to douche it with brake clean and fluid film🤣

[@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

[@jonharris794]

If it was an Astro van it would be that broken vacuum line.

[@TreyCook21]

Or my '94 Jimmy that goes HHHHHHHGGGGGG (air suck noises) when you flip it to defrost.

[@Dirtyharry70585]

Wouldn’t have taken 20 yrs either👍🏼

[@douglasjreynolds]

Yup, takes about 2 years or about 50k miles. Fixed a few in the parking lot.

[@jeremywinkfield8523]

Petrol price UK approximately 5.50 dollers per US Gallon. Just saying.

[@davidhinkle2207]

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

[@kennethalbert4653]

SUBSCRIBED !! You are a 1 in a million mechanic, literally.

[@higgins7965]

WWID? What would Ivan do? JB weld to stop gear turning too far?

[@unclemarksdiyauto]

You know Ivan would!

[@russdavis1960]

I was thinking a small blob of hot glue.

[@jimpie231]

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

[@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 👍👍

[@joryfarr4840]

You're not the hack General Motors is the hack put something in that'll work and stay working thanks Eric great video

[@AntonioClaudioMichael]

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

[@OzFrog48Z]

I didn't see this video when it came out two months ago. I've seen some GM vehicles with inoperative mode doors that have to have a relearn procedure done . As the components wear, the position sensor voltage changes and the controller won't function because the learned position voltages are different. Sometimes a relearn procedure will let the controller relearn the voltages at either end of the potentiometer sweep. I can't recall from memory how to do the relearn. Might be worth a try on the next one that comes in.

[@korton3665]

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

[@rons4452]

How do you like working on foreign cars?

[@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.

[@MegaDysart]

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

[@ckm-mkc]

The tape on the control was a good indicator of a endemic problem with this system. Someone taped it over so no one would move it to defrost....

[@wdhewson]

Arizona heat degraded the foam ??

[@jhonditch4269]

that foam degrades in any conditions.

[@christopherj9494]

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

[@reggiecard2918]

REALLY A SHAME THEY DIDN'T BUILD IN A LITTLE " WIGGLE ROOM" IN THAT SOFTWARE IN THAT SOFTWARE TO ACCOUNT FOR GASKET WEAR.

[@2dfx]

Classic GM engineering

[@spelunkerd]

Brilliant, practical troubleshooting. If that plastic part were designed to limit movement beyond its normal sweep, this would never happen when foam disappears. On the other hand, by allowing a little more sweep, they allow doors to close completely. I can see why they are designed to flip into a 'no move' mode. If the door breaks, the module wants to detect that and not dangerously flog a stuck motor. And as you say if the actuator sensor is wide open 5V you have the appearance of a circuit fault as well.

[@dpeagles]

Nothing warms my heart more than seeing "made in china" on those dampers. Not.

[@dpeagles]

@@lesoram6236 🙄

[@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.

[@jeffreybegeman9544]

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

[@Tommy_Mac]

Great video! You are lucky it isn't a later model with the console, like on my 2005. Both front seats and the console have to come out to get to the heat/defrost actuator. Replaced all 4 actuators, which requires the top of the dash as well as cutting a duct to remove the passenger temp. actuator. Actuators= POS

[@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!!!!

[@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.

[@sjgoff]

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!

[@davidmueller2780]

Mine is stuck on defrost because the lever slips out of position on the actuator gear

[@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.

[@knightnrmer]

Good Fix .... now if they make a meter to see why my wife is not defrosting I'd be all set .

[@markh.6687]

"I tried re-wiring her, tried re-firing her, think her engine is permanently stalled. She's so cold she's so cold cold cold/like a tombstone!" (Rolling Stones, 1980)

[@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.

[@brucel.6078]

Damn good video!!! U rock, dude!

[@SharkDude1]

When your air vents are throwing things at you, you might have a problem.

[@wirenutt57]

Well, there's your problem, lady!

[@davidd5454]

I have the same problem on my Tahoe but its with the temp blend..gets stuck on full hot.. I just put a stop in the control knob to prevent from going full hot

[@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!"

[@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.

[@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!

[@Mr.Humphrey60]

Thank you SMA THE AUTOS SAME SHIT BUT WE LUV S.M.A MUCH Respect

[@kenknerr7226]

Dude, go to Lowes and get some DIY self stick weather stripping and re-foam the doors.

[@terryharvey4811]

ITS NOT THE COST OF THE DOORS , IT'S THE LABOR CHARGE TO REPLACE THEM THAT GETS YOU IN THE POCKETBOOK..

[@skylardelaney5041]

That actuator was replaced between cuts? First 2018 then 2020? Something fishy is going on here.. 👀👀

[@SouthMainAuto]

Customer had already purchased a new OEM one. Just to be sure I wasn't crazy I tried it but knew it wasn't gonna work. He told me to just leave it in.

[@pootthatbak2578]

That climate control has a 2018 chy - na actuator, i dont believe oem was chinese. Eric, gm making a fool out of all of us!! That system sucks. Those actuators suck..there is a relearn mode that has paid millions of dividends to the dealers for just resetting the hvac system by pulling the fuse

[@pootthatbak2578]

P.S. this video will get heavily searched..very common problem, all 3 blend door actuators. The early years had broken gears, the later ones, 2009 thru 2014 just sucked.

[@troymurphy6471]

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

[@Buckswoodshop]

I feel like a winner, I said to myself why not put a screw in it to stop it? Nice work 👍👍

[@amythompson6494]

Very helpful diagnosis. Had similar issue in 2008 Silverado. Hey everyone! Let us get Eric over the 800,000 subscribers. If we all share and subscribe we can get him there quickly to keep getting out great information and helpful videos!

[@briansterenberg8119]

Thank you so much for this video! That little screw is the only thing that worked to fix my son’s Tahoe 👍

[@richardspees841]

I wondered how long it would take you, or if you would, decide to just limit the travel a bit. I should have realized that you would get around to it eventually. :)

[@int53185]

The customer states "Screw it!" And "there's your dinner!" Reference to which YT channel?

[@Vincent_Sullivan]

Taryl Fixes All...

[@AntonioClaudioMichael]

Wonder if the white arm is clocked wrong and allowing it to go past its normal range 🤔 @SouthMainAutoRepairLLC

[@SouthMainAuto]

I pulled it to look, only goes on one way. It's keywayed.

[@AntonioClaudioMichael]

@@SouthMainAuto awwww makes sense that is defenitly a interesting weird problem haven't seen that before