1998 Toyota Estima - heating/air conditioning - pondstrider

The sliding temperature contol is doing strange thngs.. If its put hard left, I get cold air conditioning. If I move it even slightly towards the right, I get constant hot air... Car is thus either too cold or too hot all the time! Any ideas would be welcome...

1998 Toyota Estima - heating/air conditioning - Wackyracer

which type of control system do you have, There are 2 types. One is electronic and the other is cable operated. The cable operated one has 4 buttons along the front edge.

1998 Toyota Estima - heating/air conditioning - pondstrider

Haven't got 4 buttons... just two sliding controls for temp and blower speed, and a hazard light to the left of them and the inside/outside air switch to the right of them...