Current remaining after flipping master switch?

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Frankenfish

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Hi everyone, I had a quick question. I wired my boat up as below:
Battery+ :arrow: Master Switch :arrow: Fuse :arrow: Device Switchboard :arrow: Device :arrow: Battery-

Last night, I was testing things out and noted that if I turned off the master switch, then flicked one of the device switches, I would get a short flash out of the device (in this case a small LED light strip). Is this normal to have a small amount of current stored in the wire after turning off the positive from the battery? My outboard is in this same circuit (not running) so is it supplying the short charge? If there were a capacitor, I suppose it could supply a charge even after the positive from the battery was cut off?

Thanks in advance for any advice!
 
If the motor is connected directly to battery, it is unlikely to be the motor. It is removed from circuit when master switch is off.

Is motor a remote?

What other devices are connected between fuse and device switchboard?
 
I would bet that some device in the circuit has a capacitor as part of the circuitry. Capacitors store electricity. When you flip that switch, you are discharging the capacitor.
 
The motor is a tiller with electric start, the motor is also wired into that master switch so that I have a single kill switch for all electronics in the boat (minus trolling motor on it's own circuit) in case of maintenance or emergency. The way it's set up, should the motor hold a charge, I'm pretty sure it would be able to then act as the positive to the rest of the circuit until that charge was depleted. The motor is a new Merc 20hp tiller with electric start.

There is nothing between fuses and switchboard, masterswitch goes to the fuse block and motor and fish finder (not hooked up at the time when noticing the issue). The fuse block has individual fuses for each device, shoots current to the individual switches on the switchboard, the switchboard is then connected to an LED Flood light, a few parallel'd LED strips, a bilge pump, 10 year old navigation lights, and a voltmeter/usb charger/cigarette outlet combo thingus.

Thank you both for weighing in!
 
Frankenfish said:
The motor is a tiller with electric start, the motor is also wired into that master switch so that I have a single kill switch for all electronics in the boat (minus trolling motor on it's own circuit) in case of maintenance or emergency. The way it's set up, should the motor hold a charge, I'm pretty sure it would be able to then act as the positive to the rest of the circuit until that charge was depleted. The motor is a new Merc 20hp tiller with electric start.

There is nothing between fuses and switchboard, masterswitch goes to the fuse block and motor and fish finder (not hooked up at the time when noticing the issue). The fuse block has individual fuses for each device, shoots current to the individual switches on the switchboard, the switchboard is then connected to an LED Flood light, a few parallel'd LED strips, a bilge pump, 10 year old navigation lights, and a voltmeter/usb charger/cigarette outlet combo thingus.

Thank you both for weighing in!

It is very likely just the capacitors in the outboard ECM backfeeding. It's normal, and there is not really much that you can do about it.

When hooking up something relatively new with any sort of control module, you'll get a pretty good spark from those capacitors charging up.
 
Based on your wiring, I would agree with others that your engine is back feeding the lights.

To verify, disconnect the engine positive lead from switch and turn master to off, light to on, and you should not have any lights at all.
 

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