To Heat Or Not To Heat

[MJW602]

Hi all, greetings from AZ!

I've been lurking around the forum for quite a while and have picked up some very useful information. Everyone on here is so knowledgeable and I'm hoping I can get some insight on my situation.

I purchased a new to me 2003 Yukon SLT w/173,000 miles that I lovingly named Ruby because of her beautiful maroon color. I paid $2500 for it, and I knew going in that there were some things that would need to be addressed. In short, I've spent $3000 on repairs and upgrades in the 6 months I've owned it with the biggest expense being a rebuilt transmission.

One chilly morning about a month ago I discovered Ruby has no heat
I had my mechanic look at it and he determined that in order to fix it the airbox will have to be replaced which will require the dash to be torn apart and will be quite costly

In hindsight, I bought the truck in June when it was 100 plus degrees outside so at that time I was mainly concerned that the AC was blowing ice cold. I didn't even think to check the heater.

Fortunately, I live in AZ so the winters aren't super cold but some nights it can get down into the 30s.

What do you guys think - is it worth the additional expense to get the heat fixed?

 

[iamdub]

Can you elaborate on why the airbox will need to be replaced? It's just not one of those things that gets replaced. Components on and in it, sure, but not the whole thing.

The heater is a simple system- its just a radiator (the heater core) that water heated by the engine flows through. A blower forces air through the heater core, heating the air, which then blows out through various ducts. The ducts which the air is blown through are controlled by actuators that open and close flappers. The temperature of the air is controlled by other actuators and flappers that blend in cool outside or inside air with the heated air.

No heat means either your heater core is bypassed or an actuator isn't switching over to heat.

 

[MJW602]

Can you elaborate on why the airbox will need to be replaced? It's just not one of those things that gets replaced. Components on and in it, sure, but not the whole thing.

The heater is a simple system- its just a radiator (the heater core) that water heated by the engine flows through. A blower forces air through the heater core, heating the air, which then blows out through various ducts. The ducts which the air is blown through are controlled by actuators that open and close flappers. The temperature of the air is controlled by other actuators and flappers that blend in cool outside or inside air with the heated air.

No heat means either your heater core is bypassed or an actuator isn't switching over to heat.

The 2nd one, the actuator isn't switching over to the heat per my mechanic. He initially diagnosed the problem as a bad blend door actuator. When he got under there to switch it out, he told me that there is a piece the actuator needs to hook into that's missing. That's when he told me in order to repair the problem he would have to tear apart the whole dash.

 

[iamdub]

Hmmm. Wes and others are more versed on this sort of thing. I've never torn one out of one of these rigs.

@Doubeleive

 

[Doubeleive]

Hmm although it may be possible the blend door broke it is rare, you can check it yourself pretty easily with a 7mm socket and a 5.5mm socket, the hot/cold actuator is one of the easiest to access it is right under your glove box, I would watch a couple youtube videos and then inspect it yourself to verify the issue is indeed a broken door

i will add that if it is a broken blend door my butt would out in the junkyard sawing that piece out of a used truck and patching it in rather than spending $1100, but that's just me, dorman makes some repair kits also not sure if they make one for the gmt's though

 

[swathdiver]

The 2nd one, the actuator isn't switching over to the heat per my mechanic. He initially diagnosed the problem as a bad blend door actuator. When he got under there to switch it out, he told me that there is a piece the actuator needs to hook into that's missing. That's when he told me in order to repair the problem he would have to tear apart the whole dash.

There are lots of videos on youtube on ways of doing it, some smarter than others so beware! If you have the time, it's not really a tough job, just lots of steps and things to do.

 

[MJW602]

There are lots of videos on youtube on ways of doing it, some smarter than others so beware! If you have the time, it's not really a tough job, just lots of steps and things to do.

Hmm although it may be possible the blend door broke it is rare, you can check it yourself pretty easily with a 7mm socket and a 5.5mm socket, the hot/cold actuator is one of the easiest to access it is right under your glove box, I would watch a couple youtube videos and then inspect it yourself to verify the issue is indeed a broken door

i will add that if it is a broken blend door my butt would out in the junkyard sawing that piece out of a used truck and patching it in rather than spending $1100, but that's just me, dorman makes some repair kits also not sure if they make one for the gmt's though

Unfortunately, I am not mechanically inclined at all so

Hmm although it may be possible the blend door broke it is rare, you can check it yourself pretty easily with a 7mm socket and a 5.5mm socket, the hot/cold actuator is one of the easiest to access it is right under your glove box, I would watch a couple youtube videos and then inspect it yourself to verify the issue is indeed a broken door

i will add that if it is a broken blend door my butt would out in the junkyard sawing that piece out of a used truck and patching it in rather than spending $1100, but that's just me, dorman makes some repair kits also not sure if they make one for the gmt's though

That is the price my mechanic quoted me, about $1100 to do the repair. As much as I love my truck it would hurt me too bad to shell out that kind of money.

Unfortunately, I am not mechanically inclined at all so when it comes to making any type of repairs I am completely at the mercy of my mechanic. I tried looking at a couple of youtube videos but honestly they may as well have been speaking Greek lol. My mechanic suggested that I get one of those portable heaters but I researched some and read a lot of unfavorable reviews.

 

[Doubeleive]

Unfortunately, I am not mechanically inclined at all so



That is the price my mechanic quoted me, about $1100 to do the repair. As much as I love my truck it would hurt me too bad to shell out that kind of money.

Unfortunately, I am not mechanically inclined at all so when it comes to making any type of repairs I am completely at the mercy of my mechanic. I tried looking at a couple of youtube videos but honestly they may as well have been speaking Greek lol. My mechanic suggested that I get one of those portable heaters but I researched some and read a lot of unfavorable reviews.

then try another shop, I mean for about a cheap $20 small socket set you could check it out yourself, 2 bolts out and you can pull the bottom shroud out enough to access the actuator and look in there with a flashlight. we can help you man, that's why you came here right?

 

[Don in Mesa]

Hi all, greetings from AZ!

I've been lurking around the forum for quite a while and have picked up some very useful information. Everyone on here is so knowledgeable and I'm hoping I can get some insight on my situation.

I purchased a new to me 2003 Yukon SLT w/173,000 miles that I lovingly named Ruby because of her beautiful maroon color. I paid $2500 for it, and I knew going in that there were some things that would need to be addressed. In short, I've spent $3000 on repairs and upgrades in the 6 months I've owned it with the biggest expense being a rebuilt transmission.

One chilly morning about a month ago I discovered Ruby has no heat
I had my mechanic look at it and he determined that in order to fix it the airbox will have to be replaced which will require the dash to be torn apart and will be quite costly

In hindsight, I bought the truck in June when it was 100 plus degrees outside so at that time I was mainly concerned that the AC was blowing ice cold. I didn't even think to check the heater.

Fortunately, I live in AZ so the winters aren't super cold but some nights it can get down into the 30s.

What do you guys think - is it worth the additional expense to get the heat fixed?

-----------------------------------------------------------------------------------------------------------

Bought my 2006 Yukon SLT with 129,000 miles, TH SAME WAY YOU DID - IN THE SUMMER.
Like you - I think I should have not assumed the heater would work like other vehicles I have owned.

Have read all the answers you have gotten, so I can begin troubleshooting mine.

Pushed one button and everything switched from English to French. Had a heck of a time switching back!

 

[Tonyv__]

If this helps this takes literally zero mechanic skill. Start your truck. Let it warm up to temp. Like 15 minutes. Turn on your heat. Then pop the hood and feel these hoses (circled in blue) they should both be hot. (CAUTION. They might be HOT). If they are both hot then you can rule out the heater core. If one side is hot and one side is luke warm or cold then you probably need to flush the heater core. If both sides are cool. Then you’re low on antifreeze or heater core is really blocked up


My Tahoe had a blocked heater core when I bought it. Fixed it by flushing with a garden hose.


As far as the air box. If something is missing then I’m gonna assume someone else was in there trying to fix it and somehow damaged the box... but I’d honestly get a 2nd opinion. Something has to be holding the current part in there now.