The ghost in heaters instrument panel

Dear friends, I’m struggling with heating, I have solved the problem of air conditioning and now it is time to fix the baby for the winter! Let’s start by saying that the knobs that take care of regulating the temperature and conveying warm air on one side compared to another do not show signs of life, in the sense that you feel no resistance and no particular clicks, they spin empty! The mechanism that takes care of opening the hot water in the engine compartment works but is not activated by the instrument panel. Last winter I temporarily solved it by putting a tap and leaving it always open I had warm air in the cockpit even though sometimes cold air came out anyway !! What can I check? I will certainly have to remove the control panel but in search of what? Do you have any photographs of the affected areas that you can anticipate to my mechanic?

Max, from memory there are not any ‘detents’ on the control knobs, they send a signal to small servo motor that move the blend flaps. Remove the knee bolsters and give the servos a light tap and listen for any sound of the motors moving the flaps.
Note the response isn’t instant it takes a few seconds to start any movement.

ok…i will try…but if don’t i listen anything? what must i think?

I think you will find that the blend flaps are just a little recalcitrant and need a little persuasion, the servo motors can be removed and the flaps can be exercised with a screw driver from memory.
Its a while since I had to do this.

The servo motors HATE to sit idle in one position for extended periods.

I used to have a long wood dowel to ‘smack’ the servos every once in a while to get them to operate.

The cases also ‘crack’ and the gears become jammed.


will it be possible to have a photo to recognize these servo exactly?

update … the mechanic has discovered that there is no depression, so he is checking why, it is not a problem of servo motors but something more ugly … the solenoid valve?
In the meantime, since we removed the covers, I noticed flying wires … does anyone recognize them? I state that cruise control doesn’t work, maybe it’s its cables?

Max …


The rotary knob on the left has 4 detents. You should feel a positive click as the knob is selected to each position …

O … turns the entire system off

Low/Mid/High … turns the system on (including both a/c fans and the a/c compressor) and selects speed of fans.

Def … opens the two vents on top of the dashboard to direct air at the windshield for defrosting.

The rotary switch on the right selects the temperature by positioning the two blend doors that direct air through the evaporator and heater core …

There are no cables in the system, everything is electronically or vacuum operated.

As far as the Face Vents slider knob. I’ve found it to be of no real use.

now all works…the problem was that the hoses for the depression were all disconnected. the old owner made a mess in this car … I’m resurrecting it! now it remains to understand what all disconnected cables are…

i split my question in a new thread…