Heater not working

[Merkava_4]

2000 Buick LeSabre

The air switches from the vents to the duct down below like it's supposed to, but the air blowing out feels like the same temp as the outside air. And this is with the engine fully warmed up with a water temp of +190F too.

 

[Ken42]

Is there a water control valve in the pipes to your heater core?
If so check it could be stuck closed.

Ken

 

[Dave H]

I'd check the blend door operation. I think it is stuck, only allowing cool air through. On your Buick, I'd bet you have an electric motor that opens/closes the blend door, and it may not be working right. It'll be somewhere under the dash, in the ductwork, near the blower motor housing. The door could also just be stuck from being gunked up.
When you slide the temp control knob/lever from hot-cold, check if you can hear anything going on under the dash. This will help you pinpoint exactly where the blend door is at. Then inspect the door while someone is operating the switch, and see if it moves (may have to remove a piece of the duct to see it). You should be able to figure out what is wrong from there (door just stuck or motor not working).

Dave

 

[MrCritical]

Unless the heater core is clogged, Dave is on the right track here. If you have the auto temp control, the unit itself could be defective.

 

[Merkava_4]

Ken42, Dave H, MrCritical

Thank You all for your replies. I'm being told that it's a possible Mode Door Actuator that's at fault. That for me would require the assistance of a Buick Factory Service Manual of which I don't have; and until I acquire one, I'm not touching anything.

 

[The Critic]

Originally Posted By: Merkava_4
Ken42, Dave H, MrCritical

Thank You all for your replies. I'm being told that it's a possible Mode Door Actuator that's at fault. That for me would require the assistance of a Buick Factory Service Manual of which I don't have; and until I acquire one, I'm not touching anything.

Find a GM technician from a forum. They should be able to give you the correct instructions.

AllData doesn't have this info?

 

[NYEngineer]

Do you have a Raytec thermometer? Check the supply and return sides of the heater core to see if you're getting flow.

 

[xl1200dt]

The problem is your blend door actuator which is up top of the dash. the dash has to come out. The part is about 50.00 and 3 hours labor. have to get part from dealer. I just did one on my 2000 le sabre

 

[Gary Allan]

Quote:
the dash has to come out.


I don't think we'll ever see this type of thing featured on Modern Marvels on The History Channel.

 

[Merkava_4]

Quote:
AllData doesn't have this info?


Hi Mike,

They have some, but they're limited on their HVAC under dash info.

 

[Merkava_4]

Originally Posted By: NYEngineer
Do you have a Raytec thermometer?


^Not yet, but it's on my list.

I have yet to check the heater hose temps, but will definitely do so.

Thanks for your reply.

 

[Merkava_4]

Originally Posted By: xl1200dt
The problem is your blend door actuator which is up top of the dash. the dash has to come out. The part is about 50.00 and 3 hours labor. have to get part from dealer. I just did one on my 2000 le sabre


Your first post at BITOG is worth absolutely gold to me; thanks for the valuable info!

Do any of these images look familiar to you?


Air Temperature Actuator

Mode Actuator

Recirculation Actuator

 

[xl1200dt]

It is the air temp actuator, located under the defrost vent, but there is no easy way to get to it unless you want to cut a hole on top of the dash. Dash must be removed. good luck. Thank [censored] for this wonderful site and wonderful people.

 

[wiswind]

Don't feel bad.....this issue is far from limited to this particular vehicle.....looks pretty similar to the same unit used on the FORD Windstar....and is prone to fail there.

The nice improvement that has been made over the years is that most modern vehicles have the coolant flow through the heater core all the time....and temperature is regulated by controlling how much air passes over the hot heater core.
The advantage to this is that, by having the coolant flow constantly through the heater core, you prevent coolant from sitting stagnent in there over the summer months......and you are FAR less likely to have clogged heater core issues.

 

[Merkava_4]

Quote:

AIR TEMPERATURE ACTUATOR REPLACEMENT

REMOVAL PROCEDURE

1. Remove the IP compartment.

2. Remove the electrical connector from the air temperature actuator.

3. Remove the air temperature actuator retaining screws (1).

4. Remove the air temperature actuator.


When they say "IP compartment," they mean the instrument panel glove box right? As in just the glove box and not the whole entire instrument panel right?