Electronic climate control

[bobbyfresh]

Can someone help whith a diagram or info on how the climate control works -I have fitted new switches -however none of the stepper motors work except the interior fan,the aircon does switch on , if i earth the board i do get them to work, there is a computer type harness connected to the controls where does this harness go? is it controlled through the ecu? Please help im desperate and in South Africa (which is desperation in itself)

[shpub]

The control is controlled by a micro controller on the heating board. Apart from switches and driver transistors, there is little that can be done except replace the board. The other problem is that replacing components can also damage the board if not done correctly. I have not seen a circuit diagram for the board and to be honest without the ability to program the controller it is a bit difficult.

The only thing I can think off is to check the earths connections ion the transmission tunnel, front wheel arch chassis and under the rad. If earthing the board does something then this could be causing problems.

Steve
www.tvrbooks.co.uk