95' FZJ80 Heater Issue- Air Mix Servo Motor not moving (1 Viewer)

[neversaydie]

Hey Everyone,

I recently acquired a 95' FZJ80 Land Cruiser with 195k on the odometer back in May, when I purchased the vehicle I baselined the cooling system to include replacing the Heater control valve. The heater worked fine but at some point over the summer the heater stopped blowing hot air out of the front vents (it still blows, just not hot air) the rear heater still blows hot air. I went through and double checked to make sure that there was no air in the cooling system and everything else was functioning properly. From what I can tell the air mix servo motor isn't moving, air blows, the cable which attaches to the heater control valve and the heater control valve itself both move smoothly but the Air mix servo motor itself doesn't move at all nor does it sound like the air mix flap is moving so I suspect its not getting any power.

Since winter is approaching here in Colorado, I'm trying to track down where all I should check next in hopes I have the luxury of a working heater in my daily driver so far I have:

-Replaced the AC/Heater amplifier
-Replaced the heater fuse
-Checked every wire connection I can find

I think my plan is going to be:
-to take apart the climate control unit and clean it out, clean up any corrosion and check the solder leads on the back
-swap out the heater relay in the drivers side footwell

Is there anywhere else I should be checking to trouble shoot the issues with the heater and Air mix servo motor?

 

[Thundercloud Cruiser]

Hey Everyone,

I recently acquired a 95' FZJ80 Land Cruiser with 195k on the odometer back in May, when I purchased the vehicle I baselined the cooling system to include replacing the Heater control valve. The heater worked fine but at some point over the summer the heater stopped blowing hot air out of the front vents (it still blows, just not hot air) the rear heater still blows hot air. I went through and double checked to make sure that there was no air in the cooling system and everything else was functioning properly. From what I can tell the air mix servo motor isn't moving, air blows, the cable which attaches to the heater control valve and the heater control valve itself both move smoothly but the Air mix servo motor itself doesn't move at all nor does it sound like the air mix flap is moving so I suspect its not getting any power.

Since winter is approaching here in Colorado, I'm trying to track down where all I should check next in hopes I have the luxury of a working heater in my daily driver so far I have:

-Replaced the AC/Heater amplifier
-Replaced the heater fuse
-Checked every wire connection I can find

I think my plan is going to be:
-to take apart the climate control unit and clean it out, clean up any corrosion and check the solder leads on the back
-swap out the heater relay in the drivers side footwell

Is there anywhere else I should be checking to trouble shoot the issues with the heater and Air mix servo motor?

Hey, did you ever figure this out? I’m having the same issue can’t find much about it.

 

[brockdeck]

Before I had my heater core replaced I could run high heat with AC on/recirc if I wanted. Now if I want to get hot air out of the vents, I need to turn off recirc and AC and crank it. Not a huge deal but shop said this is normal, idk if I just completely forgot? Similar issue so thought I’d share here

 

[Thundercloud Cruiser]

Before I had my heater core replaced I could run high heat with AC on/recirc if I wanted. Now if I want to get hot air out of the vents, I need to turn off recirc and AC and crank it. Not a huge deal but shop said this is normal, idk if I just completely forgot? Similar issue so thought I’d share here

OK good to know I’ll try that, I guess you never tried to replace the servo motor for the mixing valve? Thanks for getting back to me so fast.

 

[brockdeck]

OK good to know I’ll try that, I guess you never tried to replace the servo motor for the mixing valve? Thanks for getting back to me so fast.

To be clear just try it out, to me I think something was either in my case aligned incorrectly or something is not plugged in

 

[Thundercloud Cruiser]

OK sounds good. I’m pulling the servo out… I can get to it better because I have my evaporator out already so I thought it be a good chance to see if I can get it out