Heater control

[apossati]

I have a strange problem with the heater control knob on my MY2000 Griffith 500 (A/C equipped): when it's turned fully counter-clockwise (usually COLD) the air is HOT; when turned fully clockwise the air is even HOTTER; it's only when I turn it around 45° from full counter-clockwise that air becomes cold. The problem persists even with A/C engaged.
It looks like an out-of-zero problem. Does anybody have an idea about this problem?

Thank you

[david beer]

If you look upside down in the passengers foot well, you will see a variable resistor on the heater valve. This is adjustable and will/should enable it to be setup. On mine there was a white line to show the cold position.

[sideways500]

Following on from David's advice, I've been told that there are no stops to the movement of the heater matrix valve (a butterfly valve?). As such the cold setting presumably appears twice for each rotation of the valve. The trick is to synchronise the valve, the drive motor and the potentiometer on the dash (temperature dial).

I hope this helps.

[apossati]

Thank you very much for your fast response.
I'll let you know ASAP.