ign. wiring - does this matter? (and magneto Q)

Hey, just curious, we all know ign's have the A B M M S etc etc on them....

is it important that all go to their respective "poles"? or do ALL receive the same "output signal" once the key is in and turned on. Like, will my motor or ign get bunged if the 'M' wire is attached to the 'S' pole?
if anyone has a link / knowledge to share on WHY (if) this is important each wire gets put onto the correct pole
EDIT: Just found out this DOES matter, not sure WHY and how this is important though

SECOND Q:
my motor has two magneto wires that run to it. A black and black/white wire.
What happens IF the two wires got switched (i rewired the boat) around from how they originally were? (example: Black to position 'A', blackwhite to position 'B', but it was not Black to 'B', and blackwhite to 'A' -- would this matter? or does the motor just need two magneto wires on it?

THIRD Q:
i asked this before but had no answers. my motor is a 1965 33hp 'rude, and is electric start.
The junction box has NO FUSES in it -- should it not? never did...
ANyone care to enlighten on IF there should be and WHERE? i find it weird it never had any fuses... nothing on the boat, except under the bow for the nav lights

Re: ign. wiring - does this matter? (and magneto Q)

adamsnez2 said:

Hey, just curious, we all know ign's have the A B M M S etc etc on them....

is it important that all go to their respective "poles"? or do ALL receive the same "output signal" once the key is in and turned on. Like, will my motor or ign get bunged if the 'M' wire is attached to the 'S' pole?
if anyone has a link / knowledge to share on WHY (if) this is important each wire gets put onto the correct pole
EDIT: Just found out this DOES matter, not sure WHY and how this is important though

Click to expand...

Well, someone took the time to label each of those switch contacts for a reason , otherwise we could just hook up whatever wire we wanted to any terminal.

The switch is internally "wired" to perform specific connections for each of the switch positions. For example, when you turn the key to START, the B (battery) terminal is internally connected to the S (start) terminal. Connecting wires randomly to the switch terminal will result in blown fuses at best and potentially more serious damage.

Re: ign. wiring - does this matter? (and magneto Q)

To carry this discussion forward, yes -- it does make a difference for the reasons just specified. Pushing in on the key switch internally connects the "B" terminal (+12 volts) to the choke solenoid or primer system for starting. Turning the keyswitch OFF connects the two "M" terminals which kills the engine by shorting the magneto to ground. In the RUN position the "B" terminal feeds +12 volts to the "A" (accessory) terminal to run the gauges and any accessories connected to it. Ignore the labels and you WILL fry things. Moreover, not ALL switches have the same number of terminals and labels you mention. I/O's for example have a totally different switch because a battery ignition system is very different than a magneto system on an outboard.

Re: ign. wiring - does this matter? (and magneto Q)

M= black/yellow
M=black
A=purple (ignition)
W=yellow/red (start)
B=red (battery)
C=purple/red (electric choke)

last boat I worked on anyway.

Re: ign. wiring - does this matter? (and magneto Q)

since there are two M poles, does anyone have an answer to my question about them being "reversed" on the motor side of things? see my example of M1 to A, M2 to B, then switching it from what it was factory wired

thanks for the replies

Re: ign. wiring - does this matter? (and magneto Q)

The two M poles get connected together when the ign switch is off. it doesn't matter which one is magneto killer wire, and which one is ground. If you have two magneto killer wires pulled thru to the dashboard, they need to go each to an "M" pole.

Re: ign. wiring - does this matter? (and magneto Q)

Chris1956 said:

The two M poles get connected together when the ign switch is off. it doesn't matter which one is magneto killer wire, and which one is ground. If you have two magneto killer wires pulled thru to the dashboard, they need to go each to an "M" pole.

Click to expand...

ya, two to the dash.
i was just wondering because one goes around the flywheel area [somewhere] and the other is attached around the side of motor.
so was just wondering if swapping them on the ignition made a dif. or not

Re: ign. wiring - does this matter? (and magneto Q)

Chris1956 said:

The two M poles get connected together when the ign switch is off. it doesn't matter which one is magneto killer wire, and which one is ground. If you have two magneto killer wires pulled thru to the dashboard, they need to go each to an "M" pole.

Click to expand...

I was having problems with my ignition switch this weekend and I did not connect those two wires to anything cause I was somewhat stranded at home and did not have my volt meter here, figured I would check it out later when I had a meter handy. will it cause any damage leaving them disconnected? or does it need to be hooked up to protect the electronics? In the main harness coming form my motor I have a ground wire(black), tach wire (white), and generator wire (purple) that are currently not hooked up. my motor is a Chrysler 115 if that matters