AD says 2 wires for diesel and 3 wires for petrol. I know this is AD we are talking about though .
Roger,
AD says pin data for D1 which is the one going to the lamp is 1V ign on and 11-14V engine running. If that is correct it would seem to indicate that yes it is the traditional way but I don't understand the 1V. The data for C50 (from the alternator) is exactly the same. If it is a 2 wire perhaps Mark can answer why it has 1V instead of 0V. Floating earth maybe?
Regards,
Bryan.