Defroster/heater control question

[SethM]

Got my "new" 1985 SR5 T4WD back on the road this weekend after changing the front crank seal to address a NASTY oil leak (did the cam seal and changed the water pump (and o-ring) while in there). On the test drive, I noticed that while the heater was producing lots of heat and the blower fan moved lots of air, I had zero defrost action. A bit further inspection revealed that it seems to make no difference at all where the air control setting is set the only place that gets a steady blast of air are the "face" ducts in the dash (one on each side and the one in the middle directly above the air/temp controls). If I shut these there is no noticeable difference in the non-existent flow to the defrost outlets or the heat/floor outlets.

I did a search and found a rather long thread on the general subject but nothing addressing my particular case which seems to be that the air (direction) controls are not working at all. Again, the heater valve is working fine as is the blower. Are the directional controls vacuum operated or mechanical (like the heater control valve)?

Thanks,

[Petros]

Sounds like the large flaps are not changing position when you move the lever. Crawl under the dash and check to see the cable ends are connected to the flap levers on the sides of the heater box, I seem to recall there is at least one on each side. if they are connected observe their action when you move the levers, if they do not move the cables became disconnect off the level assembly and you have to remove it from the dash to get to the back of it.

It is also posible that there is a large amount of debris or even a mouse nest in the heater box preventing the correct airflow, or even allowing the flaps to move to direct the air to the correct ducts. If that is the case you have to remove the ducts and pull out the debris, it should not be necessary to remove the heater box, just the ducts leading to it.

[ARCHINSTL]

To add to this...I take it you have found the several threads on heater functions. I questioned this a couple of years ago and then noticed that the OMs I have mentioned that "...most of the air is directed to the foot/defroster..." I've found that (at least some) air always comes out the defrost vents, regardless of the control setting - and ditto for the "floor" setting.
It seems that air cannot be fully dedicated to any one function, regardless of the cable adjustments.
http://www.tercel4wd.com/forums/viewtop ... ost#p11949
Along with working on cable adjustments, you might take a vac with a skinny tube attached and insert it into the defroster outlets and/or remove the defroster vents from the system (bigga PITA) - I found various debris in my defroster vents, including coins. It is also possible someone stuffed something in the vents to increase flow to other vents.
Tom M.

[takza]

You need to pull the heater control panel and lube all the pivots and cables and adjust them per the FSM.

[SethM]

Problem solved! Afterpulling the control panel off, removing the glove box and some of the ducting to try and get a better look, I realized everything was attached and working at the control panel end of things. The heat/face/defrost control is connected to a single cable leading off to the drivers side so I peeked under the dash above the gas pedal and found the end of the cable had come off the flapper valve.....BTW, I couldn't find this in the FSM- what section is it under?

Thanks all- driving with new struts AND defroster action now.

[ARCHINSTL]

It's not. There is very little in the FSM about the heater.
About the best you can do is to read through the FSM's AC section on the cooling unit removal - then look at the heater section in the excellent EPC link in the Parts Forum sticky - and then go to http://www.autozone.com. After entering your car, go to the Repair Guides section and drill down in the Electrical section; this has a lot more info (and pix) about the heater than does the FSM.
It's as though Toy wanted to keep the heater info secret - kinda like it did with the ECU.
Tom M.

[takza]

My Bentley manual has good instructions on how to reset the heater controls...maybe I could scan and post it sometime.

[SethM]

...maybe I could scan and post it sometime.

That would be really helpful! As noted above, the Toyota FSM is, well,..... silent on this general area.