The heat on the wife's 1992 Previa will not totally shut off when the dash leaver is pushed to the full blue/cool range. It mostly does, but on hot days you can notice heat still coming from the vents.
Question...is this a likely failing heater control valve?
Thanks!
Okay...did some deeper looking...and noticed the cable was simply held in by a clip, so I popped it off, and made an adjustment. In removing the cable, I saw that there was some binding to the valve and cable, so I lubed them. Might have solved the problem, but if not, I suspect the seal on the valve is bad...maybe if I am lucky there is not a seal : )
Here are some pics to accompany this thread for others with this problem. It is a common one. Often the culprit is the clamp which holds the cable at the valve has come unclamped and the cable has shifted so the lever on the dash cannot close the valve fully.
The pic below shows the valve in the fully closed position with the rotating lever on top of the valve butted up tight against the tab on the mounting bracket. Note on the left of the pic the clamp holding the cable has popped up allowing the cable to move.
DSCN4640.jpg
Here's the clamp pushed down how it should be and the valve in the fully open position.
DSCN4641.jpg
After you've adjusted the cable and clamp and tested the dashboard lever to check that the valve fully opens and closes correctly, give the clamp a squeeze with pliers where it folds under its bracket to help it not come undone again.
Last edited by Jonny; 08-02-2020 at 02:33 PM.
There is a seal of sorts on the valve - a plastic sleeve inside between the housing and the part that rotates. I cut mine apart some time ago when mine stopped working properly. I had to replace mine to solve the problem.
1 -Something inside Previa heater valve.jpg
2 -Gasket extracted from heater valve.jpg
3 - Exploded diagram of heater valve.jpg
"If you find yourself holding a sledgehammer or a crowbar, it's time for a break."
Reply With Quote
