here...maybe this pic will help better explain how they are wired. This way you can see how the batts are connected on the back side of the switch....and how the battery is being selected when you switch between 1/2/all

i cropped out the alternators for less confusion......

Great!
Picture is worth a 1000 words.

So if it were hooked up in reverse, it would still do the same functions. Just gotta think of pushing instead of pulling.
If both switches are in the same position,(on either situation) that would mean both motors are trying to charge that 1 battery???? Is that a bad thing?
I always keep 1 switch set on '1', other on '2', unless I have a dead battery, then put both on 'both', then switch back afterstarted.

Thanks

EDITED>>>>>>>>>>
I GOT IT. Days off work create too much freee time.

Using the above picture with Port Engine1, Switch1 in #1 Postion(1P), and Battery1 and then same for other side, E2, S2,B2, ... except switch in #2 position (2P).

If B1 fails to start E1, you just change S1 to P2
BUT, if wired the other way and B1 doesn't start E1, you have to change the OTHER SWITCH,... S2 to P1

Right?

Good job Wally.... USA... I suggest even if you have a dead battery... the only time to have the switch on "both" is when the batteries are low and you need energy from both to start the motors. The charging systems work best when one alternator is charging one battery. The regulators get "confused" when there is a higher voltage coming back at them. If you have both alternators connected... one will override the weaker and that alternator will "sense" that the battery is charged and will not put out any power. Accessory batteries that aren't used for starting but are used for cabin lighting and other things are usually seperated from the other batteries by a big diode that only lets the electricity flow one way.

Yes....now you got it......but.....(theres always a but right! ) it onloy works if its wired the way its pictured.........you can also have it wired were B1 is wired to P1 on engine1 and on the second switch it will be B2 wired to P1 for engine2 and then the wires go from P1 on each switch to P2 on opposite switch......in that case you would run each switch in #1 position for each engine......then if you need to get power from the other battery you switch to position #2

I like the way mine is set up. Three batteries, one starts Port, two starts stbd, everything else is hooked to #3. Three way isolator means any engine charges all batteries. No switches (which freaked me at first). Never have a dead battery and if you kill the house battery, just start an engine.

Just be careful and check with the manufacturer of your boat. Cigarettes are set up so that each switch controls that battery for that engine. Hence, on my boat, both switches are to be set to "1". That way, one battery and one alternator per engine. Running one switch on 1 and the other on 2 (on my boat) is using one battery for both engines. Setting the switches on "both" will potentially fry your alternators!!!

Craig

What the civil servant said! On Cig's anyway.