curlywurly

Recently had some cold weather and noticed that the front window demister setting is not working, little to no air comes out of the dash vents near the windshield. The blower motor works, heat does come out of the mid level cabin vents, and the A/C blows nice and cold.

I have tried the HVAC trouble codes and I think I have a code "I", I can't remember exactly what that means as I have lost the link to 2002 TL trouble codes.

I removed the vent control motor near on the drivers side by the gas peddle, I can move the mechanical parts by had easily so no parts are jamming or sticking, it also does not direct air to the windshield but to the floor and middle vents, so I believe this is not the control for the windshield vents. I also took the vent motor a part, it looks fine, all greased up, contacts look good and and now broken teeth, trying any of the HVAC controls illicit no movement from this motor.

So, where is the control motor for the windshield vents?

I suspect I may have 2 faulty motors.

curlywurly

Reading Skirmich past posts about this, I might have something else going on...maybe.

Skirmich
"There are 3 Motors for the A/C System:

The "A/C Air Mix Motor" = The one that Opens/Closes the door from Cold/Hot and Opens the Heater Valve. < This DIY Motor

The "Mode Control Motor" = The one that re-directs the air from Front Vents to Foot Vents and Etc."

The "Recirculation Control Motor" = The one that changes from Inside Air or Outside Air.

So, what I don't get is when I move the Mode Control Motor linkage manually (with the motor detached) air blows out the foot vents, front vents but at no point does it change to the demist/windshield vents, so what could possibly cause this? The temp control works fine, from hot to cold, not sure about recirc though.

Iggy

Just to be clear, you are working with the linkage on the driver's side which is the mode control side?

curlywurly

Correct, I have worked on the motor control unit that is on the drivers side (LH side) slightly above the gas pedal. I have not electrically tested it in isolation from the controls levers though, I will do that next, but internally it looks fine, and all the linkages move by hand. If it works in isolation (detached from linkages) then I'm not sure what could be up, and I could be working on the wrong one any way, as when I move the linkages manually at no point does air come out of the window vents, however, when moved manually it does change the air from the floor the mid level dash vents. This is where I'm confused, no matter how I move no air comes out the windshield vents, and if I have read the above correct, the Mode Control Motor, the one on the drivers side should be the one that directs to the windshield vent yet it doesn't.

curlywurly

Assuming the blend control works (Mode Control Motor, the on in the drivers, near accelerator), what else could stop air coming out of the demist windows vents?

curlywurly

Ok, had another look, manually moving the arms and levers (it was a little stuck) does indeed move the air flow to the window, so looks like the mode motor is out.

curlywurly

All fixed, took the old mode motor apart, greased and cleaned it, put it back on but it only works once then fails again, so got another from the junkyard ($11), installed and it now works fine.

I also got an air mix control motor from the junkyard, just in case, but it looks like I will not need it, glad really as it was a PITA to get out and I wasn't looking forward to installing that sucker!

Iggy