My 1985 8v GTi has the usual heater problems (no heat once engine is properly warm).? As part of my diagnostics, could someone whose heater is working properly and has the bypass valves fitted, please confirm where they are fitted.? Is the black plastic one fitted in the return line (ie conected to the metal return pipe) and the ally one in the matrix feed line , or vice versa?? Could you also please confirm the orientation of the ally valve (ie twin conection to the front or rear of the car)?? Mant thanks,
