I bought all new gauges and I wanted the underside of the dash to be really clean. So I am rewiring the 12v and Ground but using existing signal wire. It was quite messy under there. I am assuming the B+ terminal is where a wire would be attached to on the keyed ignition switch and deliver power to the gauges when the key is in the on position. I have not messed with cranking the engine.
Voltage at the battery is 12.6vdc
Thanks,
Eric
If it showed that while cranking, I'd say it is OK, but if that is just "key-on" it's not good. Have you checked the voltage at the B+ terminal of switch with key on?
Next test. Connect voltmeter positive lead to the B+ terminal of switch and the negative to the "Ign" terminal. Turn key on and read meter. tell me what you get.
If the boat starts and runs, what is the voltage AT THE BATTERY?
What sort of rewiring did you do?