Driver's side heat works, passenger side heat does not work

Greetings from Der Faterland. I'm in Germany and it's cold tonight. I have a 2003 4Runner, SR5. Turned on the heat and noticed I have great heat blowing on me on the driver's side. Wife's side? It's like blowing outside air, freezing cold. Kinda like her mood right now. Same symptom on the floor, dash and defrost: hot on my side, cold on her side.
Does each side have a blender and blender actuator? Can't find help in my Haynes guide and so far, haven't found the answer online. 8:30PM here, so going out to work on it isn't an option. I think what I've learned so far is that I need to take out the glove box and see what I can find.
Anybody have some suggestions, photos or deep thoughts?
Thanks in advance.
Lestoil

 

Sounds like the exact opposite of what happened with my truck...

My A/C would blow ice cold on the driver's side, but warm/outside temperature on the passenger side. Ended up being a leaky evaporator core...

Perhaps you're low on coolant and/or have a leak in your heater core?

 

Use the Haynes to start a fire in the passenger floor (in a bucket) for your wife. That's really close to what they are good for. IMHO of course.

Moving on, seems like I've read about something similar around here, and maybe even how to fix it.

@Jimmyh weren't you a victim of something similar in the past? Maybe it was AC related, but I'm wondering if the underlying issue would impact heat too?

 

Coolant level is GTG, Charlie. I'll look for moisture on the carpet tomorrow morning to see if the heater core is leaking. Since I'm getting heat on the driver's side but not on the passenger side, I'm thinking the heater core is OK but I have a problem with the blender being stuck or the blender actuator being on the fritz (I hope the rest of Germany doesn't think that's a derogatory statement there...).

Bill, I might just use your suggestion on the Haynes guide. Everything does server a purpose. Might keep mama warm for a while in the process. I looked up Jimmy and looked at his posts, but didn't see anything about this situation, though. But thanks for the ideas.

 

Post 12 in this thread might be a help............... https://www.toyotanation.com/forum/...-2003-2008/326990-no-heat-passenger-side.html

 

I only had an issue with the A/C where the drivers side was cool and it got warmer as you checked the vents towards the passenger side. My issue was a leak on the high pressure hose and condenser coils. Replaced recharged and no more issues. I don't know about any heat issues as it was summer in South Carolina and I never turned on the heat...

I would venture to guess a possible plugged heater core.

 

Thanks for the post and the link, Jimmy. I'll have to get out there in the morning and see what I can find out. On the bright side, there's no moisture on the carpet, so at least I'm not dealing with a leak. Took the glove box out tonight after work and replaced the cabin filter. Really couldn't see the blender and I'm afraid it's right behind the center console. Couldn't see it under the driver or passenger side of the dash.

 

OK, here is where I am so far. Recap: It's cold outside and I have heat on the driver's side but cold air on the passenger side. Do not have dual zone controls.
Today, I took out the glove box and the small storage box in the top half of the glove box. I accessed the blender actuator and I could push each of the controls on the dash (clockwise from 12: Defrost, Defrost and Floor, Floor, Floor and Dash vents, Dash vents) and I could see the actuator turning to each setting. I had the cabin filter out, so I could also see the door open to direct air up to the defroster. I could put my hands in front of the various vents and feel the change when I changed settings (meaning I could feel air coming out of the dash vents and then feel it stop when I changed settings). I could see the fan turning and could feel the difference in pressure when I turned the fan speed up or down.
So I figured everything is working as it should. Then I moved to the heater coil. I disconnected the hoses at the firewall on the engine compartment side and connected a hose to each of the heater core tubes and flushed it in both directions. I used a clear 12mm hose that fit very well in the tubes, so I could see the water flushing the core. I got a LOT of brown water at first, then changed directions when it was running clear. Got some more sediment out when I changed directions and the water was running clear. Connected the hoses and added some coolant and took her for a spin.
Results? Better heat on my side, still blowing cold on the passenger side.
I'm wondering now if the blender door is not actually moving like it should, even though I can feel the change of pressure when I change the settings. But it's going to be a son of a gun to try to troubleshoot that. Since I am getting heat on the driver's side, I really don't think it can be a bad heater core. I believe that there are two blender doors inside the blender, if the schematics I've downloaded are accurate. I'm wondering if, even though I could see the blender actuator changing positions, maybe the blender doors, or one of the doors, is not moving like it should and I'm just getting nominal flow over the heater core from that side. Maybe it's loose on the shaft or maybe the shaft is not turning like it should when the actuator changes positions. There are two screws holding the actuator bracket in place that I just can't get a screwdriver on, but I'm going to have to figure that out and get it off to see if I can physically move the blender door shaft.
Not sure if these videos will work or not, but I'll give it a shot. A little shaky, trying to hold the camera, watch the actuator and push the control buttons while looking at a pretty confined space.
https://youtu.be/s6EPHFvO5wk
https://youtu.be/13A_oFMIdFU

 

More internet searching and now I'm thinking I didn't look at everything. If this diagram is any indication, I was testing the Mode Control Servomotor and I should look just a little lower and to the left at the Air Mix Control Servomotor.

 

This cracked me up haha

 

Yep you're onto something there. That'd be the servo to check next