totallyunimodular

Just sold my 1996 T100 for an 86 4Runner and discovered that there is no hot or cold air that comes from the center vents that sit above the radio. Side vents blow strong, as do the defrost vents and the driver's side floor vent under the steering column. AC blows cold, no front heat but rear heat is fine. The front heat selection knobs seems to work as expected, just no air flow out of the center vents under any selection.

So, with respect to the lack of front heat I am hoping its just a stuck heater valve because the coolant hose running into the valve is hot while the engine is running but its noticeably cooler for the hose on the other side of the valve that then goes into the firewall. I ordered a new valve from the Toyota dealer ($80 )and will deal with that soon.

As for the center vents not blowing at all, I am confused. Looking at my Haynes manual, the front heater assembly shows the hoses that come off to go to the side vents and defrost, and searching the posts on Yotatech found plenty of people who had center vent air but not side vent or defrost, which pointed to blocked/disconnected hoses. For the center vents, it looks like the air should come straight from the heater itself through a hard, integrated plastic duct and not pass through any hoses.

One thing that is odd to me about the center vents is that there is no dial to control the rate of air flow like there are on the side vents and the vent below the steering column. There are the little thumb thingies that let you control the side to side direction of flow, which you can use to almost close the vents... When I shine a flashlight into the center vents it seems like I am looking directly into the main heater duct as shown in the Haynes manual, and I don't see anything blocking this duct.

Has anyone had this situation, or have any ideas on what to look for? I really want to avoid having to pull apart the dash, since the interior is in really nice shape and I know I'll end up cracking some piece of plastic in the process. Is there something simple I am missing?

Thanks!

stormin94

I'm thinking that you're either missing some ducting(or it's disconnected) or your selector switch for the floor vents/defroster/face vents is not working.

My side vents will blow reguardless of the selection, but the middle will only blow when the face vents are selected.

Check for air blowing under the dash, and behind the stereo when the face vents are selected to see if the ducting is missing/disconnected.

Check those things with the blower turned on max.

totallyunimodular

That's good to know about the side vents. I'll keep playing with things and report back if I find the problem. Seems like I am committed to taking the dash apart

Edit: I think the selector must be broken behind the dash because I always have air pumping out the side vents, the defrost vents, and the vent under the steering column, no matter what the selection is. Given what stormin94 said about his side vents, I am guessing that behind the dash the selector is stuck on bi-level, which would be why I am getting air out the vent below the steering column as well as the defrost.

Time to start digging through threads on repairing the selector...

Happy Turkey Day!

RobD

That's what it sounds like. The side vents on mine are on pretty much all the time. When you move to bi-level or dash only, the center vents come on, and when you go to defrost, they go off.

totallyunimodular

So I stumbled across this related thread and found the answer to my no-heat problem. Specifically, nat88Toy had this kind of side comment

When I saw that I immediately checked out my own setup and lo and behold that was it! I now have heat. Just need to fix the controller now. This forum is awesome...