2000 Yukon..Heat issues

[Doubeleive]

ok, well the blend door is the first thing that I would check, that would also explain not having cold ac as well, the door could be stuck and so you get whatever temperature is prevailing at the time or season.
good luck.

 

[ARogg619]

ok, well the blend door is the first thing that I would check, that would also explain not having cold ac as well, the door could be stuck and so you get whatever temperature is prevailing at the time or season.
good luck.

I appreciate the help! im gonna start there. Any writeups or tips for checking it? I see you said its in the passenger side kick panel correct?

 

[OR VietVet]

no, because the blend door only mixes hot & cold it does not control air flow, it could be getting stuck at 20% hot and 80% cold
it works like a Y both hot & cold air flow at up to 100% regardless if it is on 100% hot or 100% cold or anywhere in between
the door moves up and down mixing the air temperature

View attachment 237699

See, I just turned 67 on Christmas Eve and this old dog just learned a new trick. Hell, another brain fart. I know that the blend doors direct the flow of the temp and not the blower flow. The temp flow needs to enter the blower flow to get pushed out the appropriate vents. Thanks Wes.

 

[Doubeleive]

I appreciate the help! im gonna start there. Any writeups or tips for checking it? I see you said its in the passenger side kick panel correct?

Lots of youtube video's out there because it is a very common problem
before you go and just yank it out you can visually check it, there a slotted hole on the actuator, it will move when the door is commanded hot or cold or in the middle, there is 3 corresponding marks on the outer plastic that the slot should match up with when the door is commanded fully hot or fully cold or in the middle, if the marks do not line up then it is not working properly. if the slot turns and you dont feel any temp difference then it's possible the plastic door inside is broken. but you can then take off the actuator and check the door by hand.

 

[ARogg619]

Lots of youtube video's out there because it is a very common problem
before you go and just yank it out you can visually check it, there a slotted hole on the actuator, it will move when the door is commanded hot or cold or in the middle, there is 3 corresponding marks on the outer plastic that the slot should match up with when the door is commanded fully hot or fully cold or in the middle, if the marks do not line up then it is not working properly. if the slot turns and you dont feel any temp difference then it's possible the plastic door inside is broken. but you can then take off the actuator and check the door by hand.

Dude I cant thank you enough for the help. That's why I love these forums. Ill touch base after I check this thing and update you guys. BTW, I love that Silverado in your signature. I planned on buying one but the wife and I are house hunting now so I bought this cheap Yukon to hold me over

 

[OR VietVet]

Dude I cant thank you enough for the help. That's why I love these forums. Ill touch base after I check this thing and update you guys. BTW, I love that Silverado in your signature. I planned on buying one but the wife and I are house hunting now so I bought this cheap Yukon to hold me over

Wes and others here and myself are always willing to try and help but I swear, if you ever call me "DUDE" you will get the silent treatment from this old fart.

 

[ARogg619]

Wes and others here and myself are always willing to try and help but I swear, if you ever call me "DUDE" you will get the silent treatment from this old fart.

Not a problem, du.. Sir

 

[Joseph Garcia]

Dude I cant thank you enough for the help. That's why I love these forums. Ill touch base after I check this thing and update you guys. BTW, I love that Silverado in your signature. I planned on buying one but the wife and I are house hunting now so I bought this cheap Yukon to hold me over

The folks here are outstanding!! If folks here don't know, it is probably not worth knowing about.

If you are not already doing so, return the thanks by helping others out with answers or recommendations to questions that they post on this Forum.

Good luck on your repair!

 

[OR VietVet]

The folks here are outstanding!! If folks here don't know, it is probably not worth knowing about.

If you are not already doing so, return the thanks by helping others out with answers or recommendations to questions that they post on this Forum.

Good luck on your repair!

Plus, when you figure it out and get it fixed, let us all know on this thread.

 

[ARogg619]

Plus, when you figure it out and get it fixed, let us all know on this thread.

Will do. I frequent a lot of forums for all of my / my families cars. I hate when there is an issue and the OP doesn't check back in with a solution. Ill let you guys know what I come up with.

 

[mijohnst]

I'm almost done replacing my heater core right now. It involves pulling the dash complete back so that you can get the heater core/AC evaporator enclosure out. If you don't mind spending $1000 labor you might just take it somewhere. The core itself costs $25 so it's mostly labor. If you do plan on doing it yourself, I've found everyone here is super helpful. Just don't get in a hurry and break something off. If it's not loose, something is holding it.

These 2 YouTubes have been the most helpful and I've watched both several times. The first one is the best IMO. Good luck with whatever you decide and don't be afraid to ask questions.

 

[OR VietVet]

I'm almost done replacing my heater core right now. It involves pulling the dash complete back so that you can get the heater core/AC evaporator enclosure out. If you don't mind spending $1000 labor you might just take it somewhere. The core itself costs $25 so it's mostly labor. If you do plan on doing it yourself, I've found everyone here is super helpful. Just don't get in a hurry and break something off. If it's not loose, something is holding it.

These 2 YouTubes have been the most helpful and I've watched both several times. The first one is the best IMO. Good luck with whatever you decide and don't be afraid to ask questions.

$25 heater core? Tell me you got an AC Delco or GM core? What brand core did you get? Four Seasons? Etc........

 

[mijohnst]

$25 heater core? Tell me you got an AC Delco or GM core? What brand core did you get? Four Seasons? Etc........

I bought a SPECTRA PREMIUM 93050 from RockAuto. Looks like it's a popular choice. I know it's not OEM but I'm hoping that this is one of the parts that are more durable than the OEM. I'll let you know in 3 years. lol

https://www.rockauto.com/en/moreinfo.php?pk=946633&cc=1431156&jsn=2252

 

[OR VietVet]

Lots of times durability is determined by the cleanliness of the cooling system and the mileage in those 3 years. Also, if it ever overheated that extra pressure can cause problems with core units like a radiator and heater core and even plastic valves and you name it. As long as I know I am keeping my rig it will always get oe parts when I can. It is always, and should be, your choice with any of this. The labor intensity alone is enough for me to bite the bullet for oe parts.

 

[mijohnst]

Lots of times durability is determined by the cleanliness of the cooling system and the mileage in those 3 years. Also, if it ever overheated that extra pressure can cause problems with core units like a radiator and heater core and even plastic valves and you name it. As long as I know I am keeping my rig it will always get oe parts when I can. It is always, and should be, your choice with any of this. The labor intensity alone is enough for me to bite the bullet for oe parts.

I appreciate the advice. I would have paid the extra money if I'd seen this before I ordered it. It was about $75 more but more than worth it if this ever goes out.

 

[Fless]

i'm sitting here wondering why no one has suggested checking the front blend door actuator?

We were just setting it up for you to look good, @Doubeleive.

 

[2591tdj]

Is it possibly blowing cold air out one side and hot from the other, such as hot passenger side and cold driver side?

 

[OR VietVet]

i'm sitting here wondering why no one has suggested checking the front blend door actuator? if the rear works fine that means the system is working properly, that leaves only 2 likely scenario's 1. the front blend door is not working properly. 2. possible front heater core clogged but it is much less likely.
it wont cost you any money to take off the passenger side bottom kick panel and check the hot/cold blend door for proper operation, you can even take off the actuator and turn the door by hand and feel for hot/cold air to verify

When in my shops, I cannot tell you how many times I got or a tech got "tunnel vision" and could not think outside the box from the track we were on during a diagnosis. We just needed someone like yourself to jar us awake to other possibilities. Gets worse as you get older too.

 

[ARogg619]

Is it possibly blowing cold air out one side and hot from the other, such as hot passenger side and cold driver side?

Nope. all the dash vents are same temp. Just took it to lunch with some of the guys from work and the heat was working flawless. Odd

 

[Bob D]

Good Morning All,

So I have this 2000 Yukon I bought as my winter ride / work beast. As its getting pretty cold now, ive been using the heat and lately the heat from the dash is just WEAK. it takes forever to get warm if it even decides to. Now, my rear heat is perfect and warms up just as you would expect. Where should I start with diagnosing this because I want to figure this out asap before its really cold? This is frustrating bc I bought it for winter and to give my Camaro a break but I wound up taking the cover off the Camaro this morning and taking it to work after giving up on the defrost trying to clear the windshield for over 15 minutes. The truck gets up to temp just fine and no overheat issues or anything like that.

Appreciate any help,

Adam

Your Yukon has 2 different HVAC systems, since you are having trouble with the front, start by checking the blower fan as well as the coil, it my be packing with debris.