Heater not working

[thejoshw]

I have a 2000 gmc yukon, and replaced the actuator on the passenger side. Now the rear vents work great, but I am not getting any heat at all in the front. I would appreciate any help!



Thanks!

 

[David Smith]

Ever find out what was happening?

My 01 Tahoe is doing the same thing. Rear heat works great, but no heat in the front.

Actually, if I have the temp turned all the way to the hottest setting, but do not have the fan turned on, you can feel a little bit of heat coming from the vents, but as soon as I turn the fan on, it is like there is only a small amount of heat to be had. After a second, the air gets cold...

 

[David Smith]

nothing?

 

[David Smith]

It is supposed to be freezing this weekend!

No ideas at all?

 

[1999hoe]

Make your own thread might speed up responses rather than upping old ones that nobody responded to lol

 

[1999hoe]

I found this thru a simple search on another site .....

had the same problem on my 2001 Chevy Tahoe, the rear heat worked fine and the front heat was barely warm. One mechanic said I needed a new heater core for $1500, but I took it to another and asked them to reverse flush the coolant system (under $200). This worked great and the front heat is back to working again.

 

[Rocket Man]

Ever find out what was happening?

My 01 Tahoe is doing the same thing. Rear heat works great, but no heat in the front.

Actually, if I have the temp turned all the way to the hottest setting, but do not have the fan turned on, you can feel a little bit of heat coming from the vents, but as soon as I turn the fan on, it is like there is only a small amount of heat to be had. After a second, the air gets cold...

It sounds like the blend door actuator. I've never replaced mine but you can do a search on it. Edit: I'm not sure if it's the blend door or a different actuator that controls that part of the heating.

 

[David Smith]

It sounds like the blend door actuator. I've never replaced mine but you can do a search on it. Edit: I'm not sure if it's the blend door or a different actuator that controls that part of the heating.

I will look into that.

Thanks!

 

[PG01]

It sounds like the blend door actuator. I've never replaced mine but you can do a search on it. Edit: I'm not sure if it's the blend door or a different actuator that controls that part of the heating.

This^^^blend door. Fan works right? Lower the temp a little and see if that works or slowly go from cold to warm, stop before completely on hot and see where that gets you

 

[David Smith]

This^^^blend door. Fan works right? Lower the temp a little and see if that works or slowly go from cold to warm, stop before completely on hot and see where that gets you

Fan works just fine.

There is no real heat at all. If I have the fan turned off, the air that naturally comes through the vents is warm, but if I even turn the fan on the lowest setting, it blows out what little hot air there is, then it is cold.

 

[PG01]

Fan works just fine.

There is no real heat at all. If I have the fan turned off, the air that naturally comes through the vents is warm, but if I even turn the fan on the lowest setting, it blows out what little hot air there is, then it is cold.

Hows your coolant level?

 

[David Smith]

Hows your coolant level?

Coolant is fine.

Seems like it could be the blend door/blend door actuator.

It is just odd to me that hot air does come out if the fan is not turned on...There is just a limited amount of hot air

 

[PG01]

Then blend door

 

[M1Gunner]

Get the truck to operating temperature and compare the heat of the heater core hoses at the bulkhead before they go into the cabin. If one hose is a great deal hotter than the other then you have a restricted heater core and the hot coolant isn’t circulating enough. Therefor, when you turn the fans on it immediately blows whatever warmth the heater core had out and makes it cool.

It’s either that or the temperature blend door. But if you have no clicking from the dash and you can hear a noticeable change of air flow when you switch the control from cold to hot then it’s probably not going to be that actuator.

Do you have manual or auto dual zone climate control?

 

[PG01]

Get the truck to operating temperature and compare the heat of the heater core hoses at the bulkhead before they go into the cabin. If one hose is a great deal hotter than the other then you have a restricted heater core and the hot coolant isn’t circulating enough. Therefor, when you turn the fans on it immediately blows whatever warmth the heater core had out and makes it cool.

It’s either that or the temperature blend door. But if you have no clicking from the dash and you can hear a noticeable change of air flow then it’s probably not going to be that actuator.

Where ya been man?? Love that truck of yours....

 

[David Smith]

Get the truck to operating temperature and compare the heat of the heater core hoses at the bulkhead before they go into the cabin. If one hose is a great deal hotter than the other then you have a restricted heater core and the hot coolant isn’t circulating enough. Therefor, when you turn the fans on it immediately blows whatever warmth the heater core had out and makes it cool.

It’s either that or the temperature blend door. But if you have no clicking from the dash and you can hear a noticeable change of air flow when you switch the control from cold to hot then it’s probably not going to be that actuator.

Do you have manual or auto dual zone climate control?

I will have to do that.

I have auto climate control. When I have it on auto and all the way hot, the fan blows wide open, just cold air.

 

[David Smith]

I will have to do that.

I have auto climate control. When I have it on auto and all the way hot, the fan blows wide open, just cold air.

The fan blows wide open because it's freezing in my truck and it thinks it is blowing out hot air, but it isn't.

Just wanted to clarify that my heater controls are working...

 

[M1Gunner]

Where ya been man?? Love that truck of yours....

Been ridiculously busy the past couple months. Haven’t had much time of any to do anything to the hoe to share. But still try to check in here and there to see how y’all are holding up. And I appreciate it brother!

 

[David Smith]

Get the truck to operating temperature and compare the heat of the heater core hoses at the bulkhead before they go into the cabin. If one hose is a great deal hotter than the other then you have a restricted heater core and the hot coolant isn’t circulating enough. Therefor, when you turn the fans on it immediately blows whatever warmth the heater core had out and makes it cool.

It’s either that or the temperature blend door. But if you have no clicking from the dash and you can hear a noticeable change of air flow when you switch the control from cold to hot then it’s probably not going to be that actuator.

Do you have manual or auto dual zone climate control?

One hose is a bit hotter than the other. You think I can disconnect the hoses and backwash to clear it out?

 

[David Smith]

Which line going to the heater core would be the "supply"?

The line closest to the engine was cooler than the other one. From what I have read online, the one closest to the engine is the supply. Shouldn't it be the warmer of the two?