1986 40 hp Mercury need help with ignition switch wiring

[fisherman1996]

I have a 1986 40 hp Mercury Thunderbolt Ignition motor on my boat. The old ignition switch was broke so I replaced it and then lost the keys so I replaced it again but when I took it off this time I did not think to mark the wires and now I do not know which wire goes where on the new ignition switch. I have searched and cannot find a wiring diagram for my motor. Please help I also have the serial number if needed and the wire and ignition switch information below.

Wires:
Solid Red
Yellow with Black strip
Yellow with Red strip
Black with thick Yellow strip
Black with thin Yellow strip
Solid Purple also attached to kill switch
Solid Black also attached to kill switch
Solid grey only running to kill switch

Ignition Switch:
A- Accessory
B- Battery
C- Choke (Electric)
M- Magneto
S- Start (Solenoid)

There are 2 "M" spots on the switch a total of 6 spots and it says connect the cable from the engine magneto to one "M" terminal and the other "M" terminal to the electrical system ground.

 

[carholme]

Re: 1986 40 hp Mercury need help with ignition switch wiring

What is the s/n?

Gerry

 

[fisherman1996]

Re: 1986 40 hp Mercury need help with ignition switch wiring

7145373 or 07145373
I looked up the s/n on mercury and it says its actually a 1980

 

[carholme]

Re: 1986 40 hp Mercury need help with ignition switch wiring

Apologies for not getting back to you.

Yes it is a 1980:

MERCURY - ( 40 H.P. (1980 ))
Serial No: 07145373 Model No: 1040520

Parts List for model 1040520:

MERC 40 - Mercury, Mercruiser, Force, etc. Parts Lookup

Here is a link to the condensed version of the Clymer manual. Download it soonest to your computer as the link is short lived.

Small Engine Repair Reference Center Home: MERCURY - TWO-CYLINDER MODELS.

If you look closely at the M terminals, you will see that one of them is higher than the other. The lower one is the ground system.


Gerry