Poor Heating '96 FJ80

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michel77 said:
Thanks, was it the cable to the firewall heater valve or are you referring to the control arm for the footwell vents?QUOTE]

I'll sum up:
The cable to the firewall/control valve needed adjusting
The cable to the control arm near the footwell was knocked loose and barely working (now fixed)
The carpet in the passenger footwell was pulled up and completely blocking the footwell's heater vent.

Now it runs perfectly hot.
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Dont mess with the blend door. There is a single servomotor that contrals air mix (blend door) and water valve so if it is pulling the cable and controlling your watervalve it is also opening and closing the blend door. I spent way too long ripping everything apart to figure this out and even bought a servomotor because I figured that is what it had to be. It was not everything in my system is functioning properly but no front heat still. Only thing I can think of is the heater core. I am planning on doing the muriatic acid flush Mark W. outlines in the 60 series section to see if that will do it. So all in all dont rip your dash apart to check your blend door because it is working fine.
thanks
 
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Bjordnolf said:
Dont mess with the blend door. There is a single servomotor that contrals air mix (blend door) and water valve so if it is pulling the cable and controlling your watervalve it is also opening and closing the blend door. I spent way too long ripping everything apart to figure this out and even bought a servomotor because I figured that is what it had to be. It was not everything in my system is functioning properly but no front heat still. Only thing I can think of is the heater core. I am planning on doing the muriatic acid flush Mark W. outlines in the 60 series section to see if that will do it. So all in all dont rip your dash apart to check your blend door because it is working fine.
thanks
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Thanks. Was hoping you'd chime in as I read some of your previous posts on this. My issue is that the cable seems to move intermittently though, sometimes it works, sometimes it doesn't. When it does move, I get front heat fine so my heater core should theoretically be OK. I figured maybe the blend door is somewhat stuck.. You wouldn't happen to have taken any pics while you were in there would you?
 
No pics. One thing I will caution though is that the wiring harness from an aftermarket stereo could easily interfere with the levers coming off of the servo which open the blend door. Sounds like you may just have a sticky water valve? If one is working the other should be too.
thanks
 
Bjordnolf said:
No pics. One thing I will caution though is that the wiring harness from an aftermarket stereo could easily interfere with the levers coming off of the servo which open the blend door. Sounds like you may just have a sticky water valve? If one is working the other should be too.
thanks
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The water valve is fine and moves freely with the cable disconnected. Like I said with the heater valve fully open (i.e. heating position) and the cable disconnected, I still get no heat which leads me to believe the blend door is the sticky part and prevents the proper operation of both components.

There is an aftermarket stereo installed, may have gotten tangled up with the levers. How long did it take you to take off the dash? I'm planning to do this, gives me an excuse to clean out some other stuff too..

CJF said:
Because I thought you were implying there's an electronic servo motor.

I guess I'm not clear what you guys mean by "servo".
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That is what I'm implying, a servomotor that controls both the blend door and heater valve. This is what I gathered from previous threads but please chime in if this is incorrect.
 
michel77 said:
That is what I'm implying, a servomotor that controls both the blend door and heater valve. This is what I gathered from previous threads but please chime in if this is incorrect.
Click to expand...

I'm probably wrong, but:

I always assumed it was all mechanical unless the rig had auto climate control. I certainly don't get the feeling on my 91 or 92 that there're any electronics involved in the climate control system.
 
The dash has to come completely apart to get to the servomotor although you wouldnt have to go in that far just to see if your wire harness got in the way. The servomotor and levers are up and behind the radio.
thanks
 
I read all and I have exactly same issue but I have a climate control. The valve move fine and is new, the heating radiator is new , and I still not have enough heat.
 
Sorry to revive but thought I'd start some research on this:

Heat is very very scant- at full blast with full into the red I get mediocre heat. I'm not looking forward to the winter.
AC However is working perfectly, new compressor, new system refresh at the shop.

What do I need to know about the heating system that is not related to the A/C where should I start to look?
 
^^^^^If you have auto climate control, pull the unit & flip the dip switch on the back, makes it a manual unit. At least then you can rule out functionality being effed by that stupid auto-climate brain.

I’ve had 2 of the auto-climate units, the manual style like my black 80 has just works without stupid flapper door hangups, or not allowing full heat in defrost mode with incoming air & A/C on (auto-climate units only let me do that in recirc, kinda pointless).

Do you have a LX450, or a 40th/CE with that auto-climate box?
 
LINUS said:
^^^^^If you have auto climate control, pull the unit & flip the dip switch on the back, makes it a manual unit. At least then you can rule out functionality being effed by that stupid auto-climate brain.

I’ve had 2 of the auto-climate units, the manual style like my black 80 has just works without stupid flapper door hangups, or not allowing full heat in defrost mode with incoming air & A/C on (auto-climate units only let me do that in recirc, kinda pointless).

Do you have a LX450, or a 40th/CE with that auto-climate box?
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thanks for taking the time to write, I have a 1997 Fzj80. non 40th. I don't think I have an auto climate box
 
If you did, it has a huge “auto” button & the temp/color-bar had nimbers in *F here (maybe *C up there, IDK) - otherwise you just have a blue to red colorbar with a blank button in the center of the CC box that does nothing.

Are you getting up to full temp (i.e. not a failed thermostat) - if you have full travel on your heater valve that or air in the system or a plugged core are the only things that come to mind.

Is your coolant remotely recent & not some mystery sludge, and are you seeing full operating/coolant temps?

Have you opened the system or replaced the heater valve?
 
decoco said:
Sorry to revive but thought I'd start some research on this:

Heat is very very scant- at full blast with full into the red I get mediocre heat. I'm not looking forward to the winter.
AC However is working perfectly, new compressor, new system refresh at the shop.

What do I need to know about the heating system that is not related to the A/C where should I start to look?
Click to expand...

First things first: Where's your coolant gauge sitting when at operating temps?
 
CJF said:
First things first: Where's your coolant gauge sitting when at operating temps?
Click to expand...

New Koyo Rad
prestone 50/50 mix
180,690 miles
I drove from work into downtown, while driving downtown I turned the obd2
Ac on, sunny 20 D Celsius, temp at 90c or 194 F.
 
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