Yes. Consider the draw of those instruments. Transducers have large draw. So do transmitting radios and audio amps. If you want them to start “on” then use a “normally closed” relay or wire the relay to fire on power up with a momentary switch to cycle to open for emergency.fallguy1000 wrote: ↑Tue Jan 19, 2021 9:27 pmIs this why we see an instruments switch on the panel? So that we can kill power to say 3-6 items in an emergency?Jaysen wrote: ↑Tue Jan 19, 2021 6:14 pmYes. Separate switch. You need to be able to shut it off hard without needing tools.FluidDynamic wrote: ↑Tue Jan 19, 2021 4:45 pm I changed the ACR grounds. The positives are seperate isolations blocks. I guess with the sound, are you saying you would have a switch for the amp and head unit?
Consider motor alternator failure. All you want on at that point are safety equipment. Nav lights, vhf (switch to handheld), and bilge when you see it filling. Every other device should be off ensuring as much juice as possible to the motor. Even better would be small kicker you could run. Either way... kill all unneeded electronics hard.
Hope that makes sense.
ty, Dan
Personally I would use a standard illuminated on/off to trigger a relay. Leave the switch on and it all powers up with the battery switch. When SHTF (bat alarms sound) you flip the switch off and switch over to handheld vhf.