Help replacing key switch in ‘75 Mercury 500

[huck199]

I am looking for assistance replacing the key switch which is corroded, the OEM part A51015 is five pin and the replacement is Sierra MP 41000 and has six pins. They are labeled well but I am not sure what the different colored wires coming from my harness are for. Does anyone have a diagram or label that could help me out identifying all of these wires?

Salmon?
White?
Gray- Choke switch
Red?
Black?
Yellow- neutral start interlock switch
Brown-goes to tach connector
I just need to know how these colors equate to the letters on the new part (MP41000) which are:
M-magneto
I-ignition
S-solenoid
B-battery
C-choke
M-?

Thank you for any assistance!

 

[Texasmark]

I am looking for assistance replacing the key switch which is corroded, the OEM part A51015 is five pin and the replacement is Sierra MP 41000 and has six pins. They are labeled well but I am not sure what the different colored wires coming from my harness are for. Does anyone have a diagram or label that could help me out identifying all of these wires?

Salmon?
White?
Gray- Choke switch
Red?
Black?
Yellow- neutral start interlock switch
Brown-goes to tach connector
I just need to know how these colors equate to the letters on the new part (MP41000) which are:
M-magneto
I-ignition
S-solenoid
B-battery
C-choke
M-?

Thank you for any assistance!

If you don't get a reply it's because your post wasn't seen or nobody seeing it knew.....answer it yourself with the word "BUMP"....bump it bact to the top for another run. Repeat if necessary. Somebody on here knows, like Faztbullet usually knows since he used to race engines built in the 60-70 time line.

 

[Chris1956]

The original keyswitch probably had a separate button for the choke. The new keyswitch is likely push to choke, so it needs the extra terminal.

B terminal gets red wire
I terminal gets white wire
C terminal gets grey wire
M terminal gets salmon wire
M terminal gets black wire
S terminal gets yellow wire.

The brown wire connects directly to the sender pole of the tachometer.

If you are using the original MerControl, make sure the keyswitch fits in the control. Originally it was a tight fit with the 5 post switch.

 

[huck199]

The original keyswitch probably had a separate button for the choke. The new keyswitch is likely push to choke, so it needs the extra terminal.

B terminal gets red wire
I terminal gets white wire
C terminal gets grey wire
M terminal gets salmon wire
M terminal gets black wire
S terminal gets yellow wire.

The brown wire connects directly to the sender pole of the tachometer.

If you are using the original MerControl, make sure the keyswitch fits in the control. Originally it was a tight fit with the 5 p

The original keyswitch probably had a separate button for the choke. The new keyswitch is likely push to choke, so it needs the extra terminal.

B terminal gets red wire
I terminal gets white wire
C terminal gets grey wire
M terminal gets salmon wire
M terminal gets black wire
S terminal gets yellow wire.

The brown wire connects directly to the sender pole of the tachometer.

If you are using the original MerControl, make sure the keyswitch fits in the control. Originally it was a tight fit with the 5 post switch.

Yes it’s the original mercontrol, and I am honestly not sure if it is going to fit once I get the wires on. So the push to choke key will replace the separate push button correct? Thank you very much!