oh ok. so when you adjust to pure cold or pure hot or a mix inbetween with the knobs, you are essentially altering the position of the door and its ratio relative to evap core and heater core?
No heat in my truck
- Thread starter MN4runnerman
- Start date
oh ok. so when you adjust to pure cold or pure hot or a mix inbetween with the knobs, you are essentially altering the position of the door and its ratio relative to evap core and heater core?
4Reak Show
New member
Yes and that would be an astounding display of vocabulary accuracy. Ether a cable moves the door, or a little motor. But essentially all cars have at least one blend door. Dual zone climate control would have more.
And the one the decides WHERE the air goes (floor, vent, defrost or combo) is called the "mode door" for future reference. There's also one for fresh vs recirculate. That one Doesn't have a technical name to my knowledge.
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cool, all good info. thanks.
so with what you told me + this post:
http://www.toyota-4runner.org/3rd-gen-t4rs/246176-no-heat-my-truck.html#post2833332
it means the knob controls 2 things at all times you change it? 1) control valve 2) blend door
MN4runnerman
Senior Member
That is correct. If you turn the knob and look under the center console on the passenger side you can see a cable that moves a lever to open or close the blend door. No disassembly required.....well unless you need to fix it.
4Reak Show
New member
This is correct for the MANUAL systems. (Up to about 99 I think or non-limited?) However, the newer digital/automatic ones have little motors to move the doors.
oh, nice. I have a 97 limited, I'll check out moving the knob and see if I can spot the cable moving.
[MENTION=106706]MN4runnerman[/MENTION] or [MENTION=127339]4Reak Show[/MENTION] can you please help?
I now have either low to no heat after following this thread, how timely
97 Limited
1) Coolant was a little low (Below L), filled it up 50/50 up to F with Toyota Red/distilled. I probably have a leak somewhere, it's on the to-do list to pressure test with a tester.
2) I can feel both heater core hoses are hot before and after the heater core valve
3) I can see the heater core valve wire moving on the HCV when I switch from cold to hot side
4) I can see the trap door cable moving *and* I laid down backwards on passenger side and tries my best to see a door moving. Now this is where it got tricky. I'm almost positive I can hear a door open and shutting, but I can't see shit because of this black cockblocking thing in the way. I don't want to consider this step as good until I can see the damn door moving.
5) thermostat is old as shit, but it should be working properly. I have 215deg when driving around according to SGII, and I basically used to have the same exact temp a month or 2 ago when heat was fine.
6) cold as shit air blows, so the fan should be fine. and it makes no bad noises that people complain about here on T4R before cleaning it.
What the hell could this issue be? What am I missing?
I now have either low to no heat after following this thread, how timely
97 Limited
1) Coolant was a little low (Below L), filled it up 50/50 up to F with Toyota Red/distilled. I probably have a leak somewhere, it's on the to-do list to pressure test with a tester.
2) I can feel both heater core hoses are hot before and after the heater core valve
3) I can see the heater core valve wire moving on the HCV when I switch from cold to hot side
4) I can see the trap door cable moving *and* I laid down backwards on passenger side and tries my best to see a door moving. Now this is where it got tricky. I'm almost positive I can hear a door open and shutting, but I can't see shit because of this black cockblocking thing in the way. I don't want to consider this step as good until I can see the damn door moving.
5) thermostat is old as shit, but it should be working properly. I have 215deg when driving around according to SGII, and I basically used to have the same exact temp a month or 2 ago when heat was fine.
6) cold as shit air blows, so the fan should be fine. and it makes no bad noises that people complain about here on T4R before cleaning it.
What the hell could this issue be? What am I missing?
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4Reak Show
New member
[MENTION=99383]amalik[/MENTION] you probably won't physically see the door moving. That all happens internally in the HVAC box. In your picture the cable that moves the door is right in front and loops underneath to about the center of the truck. If it were me, I would pull the cable off of the nipple underneath. That nipple is connected to door inside. With engine running and hot, move the nipple with your hand all the way to each side. It should be rather hot and rather cold each way.
What I'm thinking is your cable might be out of adjustment so the door isn't fully diverting hot air only. Pulling cable off and manually running the flap with you hand would rule that out. All other indications are that its in the HVAC box. Seems like coolant flow and overall temps should give you heat, unquestioned.
What I'm thinking is your cable might be out of adjustment so the door isn't fully diverting hot air only. Pulling cable off and manually running the flap with you hand would rule that out. All other indications are that its in the HVAC box. Seems like coolant flow and overall temps should give you heat, unquestioned.
Sorry 4R, a little confused.
Thank you for the quick response.
So follow the black cable to a nipple, and pull the black cable off where it terminates, and try to move that nipple by hand?
I understand the suggestion.
My concern is... are you sure the nipple is accessible (even if a tight squeeze) from passenger glovebox? I guess I didn't try to look where the cable 'ends'.
I don't want a situation where I pull the black cable off and can't re-attach it to the nipple that controls the door for example.
MN4runnerman
Senior Member
[MENTION=99383]amalik[/MENTION] your in the wrong location. It’s on the bottom of the center console behind the plastic trim. I’m away from my trucks but I can get a picture in the morning.
Whaaaaaaa?
I coulda swore this thread said passenger glove box.
Ok so that makes more sense since freak said it wraps to middle.
When you say center console, im thinking armerest console btw, if that's what you mean.
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MN4runnerman
Senior Member
I should’ve been more clear and also revised an earlier post. Center console meaning behind ash tray. And I initially thought it was behind the glove box but it wasn’t.
I just edited first post to describe location of blend door.
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4Reak Show
New member
Yeah it should be accessible without removing anything if im not mistaken. Should be able to lay on your chest on passenger floor and look up towards middle of truck. I'm pretty sure it's very similar to my 2nd gen so I'll try and get a picture when I have time
hey man,
just an update for you and [MENTION=127339]4Reak Show[/MENTION]
so, I found the cable location after you guys told me to follow it to center console. I have plenty of heat after messing with the cable by hand, so the linkage is messed up between the sliding knob and the cable. I can't really access the dash portion of the 'connection', how do I go about fixing this and using the work-around for now?
ltsr
New member
Try some form of lubricant, specially if you got it to work after messing with it by hand. As a form of preventive maintenance, I sprayed some silicone lubricant on mine. I heard some noises coming from behind the radio and confirmed it was the blend door motor on my 01. After applying some WD-40 silicone lubricant last year, I have not had the problem. (https://wd40specialist.com/products/silicone-lubricant/)
I'm not sure about that solution for me. The knob doesn't move the cable at all if I checked it correctly, I will check again tomorrow morning.
ltsr
New member
I have a 2001 so my knob is electronic and driven by a motor. As mentioned above, yours is mechanical and the cable could have fallen off the guide or stuck somewhere. Some lubricant can't hurt as it could dislodge whatever is causing it to get stuck. Just my 2 cents. Good luck to you
4Reak Show
New member
Well at least there's an answer of some sort. Good job. Work around for time being is just to take the cable off under the dash at the door and manually set it to heat for the winter.
Is your dash a lever or a knob? Either way you're likely going to have the dash apart a bit to get to the back side of the control panel. Probably some trim pieces, maybe the stereo. I'm not sure if yours has the slide out cup holders right above the control panel. If it does you can pull the cup holders out and maybe get some eyes on in. I've seen the knob portion break (if yours is a knob and not a lever) so the cable might be totally fine.
Bottom line is you're going to have to take stuff apart to fix it right. Disconnecting the cable and manually setting the door is a short term work around to keep you comfy for the winter at least.
MN4runnerman
Senior Member
I noticed on mine(99) it has a knob that is the temp control. When I turned the knob I saw the cable to the blend door was operational but it was not opening the door all the way to let the heat in. I think my issue has something to do with the knob itself rather than the cable. The knob doesn’t turn like the one in my 98 does so I think something is jammed. For me it’s just too much work to go in and take out the hvac unit and figure out what is really wrong. So instead I bought a universal choke cable and I’m going to attach one end to the blend door and put the pull lever in an inconspicuous place. When it’s pulled the blend door is closed so then it’s cold air blowing and when it’s pushed in I’ll have heat. It’s not a perfect fix but it’ll work and it’s more of a trail truck that I drive occasionally so I don’t care. I’d honestly pay someone to remove that hvac unit it’s such a pain in the ass compared to the 01+ models where it’s a couple of wire cables. I spent almost 3 hours trying to figure out how to get it out without breaking it and couldn’t figure it out.
Thank God I don't have to go through all that crap, it seems to have fixed itself after playing with the wire and lever so much. I will try to lube the arms/pivots/etc as the other member mentioned. But anyway, for now at least -- this case is closed.
Thanks for ya'lls help!!!
PS, I have a lever - 97 limited. I'm pretty sure the cage/cover kind of just pops out for access to lights or the cable/etc.
Pic for reference
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