Boat electrical issue

[BarryBobPosthole]

my boat is set up exactly as yours is. two batteries in series for the TMs, and everything else off the main cranking battery. only diff is my accessories has a separate power switch. even though, the ignition switch cuts off the accessories when you turn the key to crank the engine and you have to repower up the DFs since they don't have On Off switches like other stuff does.

BKB

[Buckrub]

That confused me (NO SMART remarks!).

I have an accessory switch on the console also. But the only thing run through it is......um....I think the plug for (duh) accessories, like a car phone charger. It doesn't turn anything else on or off. That's how the boat came.

And why would your depthfinders not have an on/off switch. That's what is throwing me. Sure they do. So not sure what you mean exactly. And why would you want to turn those on every time? There are settings and it has built in GPS and has to 'find' the satellites all over again, and all that. I don't want them to go off and have to reset the right 'view' and other settings. Besides, I want to know what's under me when I start the big motor.

[BarryBobPosthole]

well, they have an on off switch but soon as you take away power you have to turn them on again. not so, for example for your aerator for your live wells or bilge. they just come on automatically if the switch is set to on.

and if they're on the same power circuit as the engine ignition you want to turn them off when you crank the motor because of the reasons listed by Thumper and others above. you run the risk of burning out the little naughty bits in them if you do.

if yours doesn't do this , fine.
you're way ahead of the game.

bKB

[Buckrub]

So, do your DF'ers turn off every time you start the big motor? and you then turn them back on manually every time you do that???

And doesn't the fuse stop these from 'burning out'?

[BarryBobPosthole]

mine turn off yes, every time I start the motor. and yep, the power leads are fused. and yep, I turn them all three back on every time I start the big motor if I want them on.

I'd have thought that's the way they all work or are supposed to.

The only time I've had it work differently is if I've hooked them up on a separate power circuit than the accessory one.

BKB

[Thumper]

That's how the ignition switch is "supposed" to work. That's why when you start your car, the radio, electronic dash, (or whatever accessories are on) will cut off while you're cranking, and come back on after the key returns to the run position. It not only diverts all power to the cranking circuit, it prevents damage to the electronics due to the power surge.