ignition switch swap help ??

[evilgenius877]

my ignition switch **** the bed and i have another a friend gave me off of his old non-running boat both switches have letters to indicate what wires go where but they are both different. the letters on the broken switch are marked B,M,S,A,M (clockwise, from top ,with letters in normal readable upright position). and the new(ish) switch is marked B,G,S,L,M (once again clockwise with letters in normal upright position, EXCEPT the letter B is at about the 8:00 position and the last letter M is at about the 3:00 position) i could spend all day blowing fuses trying to finger this out so some hepl would as always be much appreciated. thanks in advance.

 

[Silvertip]

Re: ignition switch swap help ??

The first thing you need to determine is whether the friends boat was an I/O or an outboard. If it was an I/O you cannot use that switch. If it is an outboard, the lets proceed.

B=Battery POS (this is the hot line from the battery)
M=Magneto (on a two stroke there will be two of these) One comes from the ignition, the other goes to ground.
S=Starter Solenoid
A=Accessory which is what all of the instruments and accessories are fed from that you want to have active when the key is in the run position. Your donor switch has this terminal labeled "L" (lights -- but means the same thing)
M=Magneto which is the second one I mentioned earlier.

As for terminal position -- it doesn't matter what the orientation is. The electrical switching is done inside the switch so the position of the terminals outside is of no consequence as long as you have the wires on the right terminal.

 

[cory13]

Re: ignition switch swap help ??

I have avery similair problem, only with a 6 wire switch. The old switch works great ,problem is the treads for the coller nut broke off anyway. The old terminals are labeled.

B,M,A,M,S,C

I'm going to assume that the C-is the choke as the switch was a push to choke, and the rest are the same as what Silvertip has described. The problem I have is that the switch I bought A (Sierra MP41000 Ignition Switch) also a push to choke is labels with has

I,S,M,B,M,C

The box labels the terminals as

M=Magento
C=Choke
I=Ignition
S=Solenoid
M=Ground
B=Battery +

I'm confused as to what happened to A, and were did I come from. I think all others are the same. The terminals are in different locations. So are I and A really one and the same or do I have the wrong switch.

 

[cory13]

Re: ignition switch swap help ??

anyone

 

[Silvertip]

Re: ignition switch swap help ??

The switch with no "A" but with both an "I" and a "S" is a universal switch that can be used on either a battery (four stroke) or magneto (two stroke) motor. On a four stroke the I terminal has power to feed the ignition system so you can pick up +12V from that terminal to feed the accessories. It serves two purposes (Ignition and Accessories). The S terminal is solenoid (or start) in either engine. The two M terminals would not be used as there is no magneto on a battery ignition system.

Using that switch on a two stroke is as previously explained. You simply don't need the "I" (ignition terminal) for ignition, but you would use it in place of the "A" (accessory) terminal.. You would use the two "M" terminals.

 

[cory13]

Re: ignition switch swap help ??

Thanks for the help, I do have one more question, will it matter which Wires are hooked to which M ? I would assume the two black with yellow wires would go to the M labeled magneto, and two solid blacks would go to the M labeled ground, but just want to be such. Thanks again.

 

[Silvertip]

Re: ignition switch swap help ??

Correct.