vyper developments

Just replaced the heater regulator valve on the Ka (no heater) as these pack up for a pastime, trouble is it still wont go to the hot position ( ie open ) irrespective of the position off the dial on the dash.

At the temp valve plug I have 12v on the purple wire and a constant earth at the green/white wire again irrespective of temp dial. this suggests to me that it is constantly in the cold position and that the control module could be faulty? New one is something like £220

Anybody had any experiences like this?

The car is non airconditioned by the way.

Thanks, Mike