Voltages

[mainexile]

Help guys! I've worked on car engines for forty years, but I'm new to boats. Mercruiser 470, early model (1978). When I measure voltage across the coil with the ignition key on, I'm getting ~1.5VDC, but I would expect to get 12VDC. Same with engine running. Any suggestions?

Thanks,
Steve

 

[wire2]

Re: Voltages

If points are open, should be 12v on + terminal to engine ground. If closed, will be less, coil primary is drawing current through a resistor.
Running should be ~6-9 v.
Keep in mind, the - terminal is pulsing between battery ground and +12 v through the coil and a resistor. You can't take a voltage reference from it.