[sallen]

I've built my MPGuino and have got it recognising the difference between stopped (0mph) and moving (some mph).

I just want to double check the connection to the injector system. I have a 1999 Mercedes Benz C-Class (petrol). It uses a HFM or PMS injection system (Siemens I think, or maybe Bosch?).

I have probed the injector wires with a digi-meter in DV volts mode (20v), connected with (+) in the plug and (-) tgoing to a bolt on the head, looking for the 0v one.

I can see there is one hovering just under (12v) which must be the power wire, but the other starts at 0v then rises quickly to around 5v.

Now I assume "injectors is injectors" so to speak, and the 5v wire is the one to tap into. Surely the Bosch fuel system on the car cannot be any different from any other injection system?

Anyone got a clue (coz I don't!)...