Ok this sounds a bit strange but check the earth on the 21 pin plug behind the heater controls. Remove the plastic strip below heater panel and this will reveal 2 screws (you will have to prise the strip off) undo 2 screws on the control panel at the top. The cover will now come off there will be another 2 screws to remove. Now check the 21 pin black wire as sometimes this melts! This happened to me and I had to strip this down on the road side so carry a phillips screw driver with you! With just the plug disconected it started and got me home
Dave Q, April 2009