Gauge wiring, request nifty trick (or skilled technician)

[FabricGATOR]

Twin SX150/LX150TXRY's rigged by others on a Bluewater sportfishing 2350.
Dual batteries, basically I run one for each engine but I can bus tie either together with dual 1-2-both switches

When I turn on the SBD ignition, three of the four gauges become active and the port engine ignition only excites its port engine tachometer.

I want either engine ignition switch to power all four gauges so if I am just running one engine (port engine in my current config), I want to see my fuel flow, without turning on the starboard ignition.

Did explain well enough? I think it is hokey that all my information is not visible if one engine is asleep. I suspect that Yamaha did a better job than that and the rigger did less than a stellar job (back in 2000) Maybe it was Y2K...

I am concocting some crap in my head with relays and diodes and I suspect that the technology is already there.

Thank you for your concern.

[boscoe99]

It is not the rigger. The configuration in your boat is the standard Yamaha set up.

Send my your email address via PM and I will send you data that shows how to make your own device so that your motors do what you want. That is, either motor will power the fuel flow meter without powering up the other non-working engine gauges.

Don't know why you would want the tachometer to be powered for a motor that is not working. But if you do, simply turn the key switch back to the on position after the motor has been stopped. Don't restart the motor. That way, all of the gauges will be powered all the time.

[rodbolt17]

it is configured per the Yamaha rigging guide.
that being said Yamaha also made a diode kit to do just as you are asking.
it is in one of the rigging guides.

[FabricGATOR]

Thank you both.
Boscoe, PM sent (shortly)