1985-1987 18 HP XD Mercury kill switch question( serial number 06633642)

My winter project is to completely redo an 18 HP Mercury outboard which I bought for a song, and is in essentially excellent shape other than the kill switch was disabled by a previous owner. I plan to repaint and install new decals and fix a couple of minor problems (disconnected kill switch and missing anode)

An ohm meter shows continuity when the kill button is pressed across the leads. However, the two leads of the switch are not connected inside the motor. One lead is obviously a ground because it has a metal connecting loop on it, but the other end has a press in connector which goes no where. When I look at the ignition module, I see a black/yellow wire that comes out of the module, but has been cut off about 2 inches long.

My question is this.

I'm assuming it originally went to the other lead going to the kill switch and any diagrams I can find do show a single connection to the motor to shunt the ignition system to ground. Am I safe to connect this unknown lead up to the other end of the kill switch

Is there any chance I could short things out and destroy some part of the ignition system. This old motor doesn't have a lot of spare parts available so I'm reluctant to take a chance. The second owner I bought it from told me he simply choked the engine to turn it off

Can someone assist...many thanks

One of the kill switch wires goes to the black/yellow wire from the switch box. The other one gets grounded to the block. Parts are very available for that motor no scarcity of parts new or used.

flyingscott said:

One of the kill switch wires goes to the black/yellow wire from the switch box. The other one gets grounded to the block. Parts are very available for that motor no scarcity of parts new or used.

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Thank you for your reply. That's what I was thinking and that seems to match up with the exploded diagrams that I have found. I will go ahead and wire it up as I thought, but it still seems strange that someone would cut that wire for no reason.

There could be a short in the kill switch check the wires carefully. They get twisted up when you use the throttle causing the wires to fray.

flyingscott said:

There could be a short in the kill switch check the wires carefully. They get twisted up when you use the throttle causing the wires to fray.

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Thanks... good thinking....that obvious reason didn't occur to me..

I'll do a further check of the loop by connecting an ohm meter and moving the handle around to see if it changes the resistance. If so, that could have been the reason why it was disconnected originally. If so, another loop and switch will be on my upcoming order of parts for this motor

Sorry to keep beating the drum on this one, but I want to be absolutely sure of my connections. In the attached photos, you will see the switchbox on my 18 HP Merc, and in one of the pics, you will see a cut off wire which is black with a GREEN strike coming out of the top right of the switchbox. Can I safely connect this wire to one side of the kill switch, the ends of which are in the third photo (one to ground and the other perhaps to this black/green wire)

I checked the handle kill switch and although it does work, it is exceedingly difficult to press in such that that is likely why someone cut it off. I plan to use a new universal kill switch placed low down on the right side of the plastic cowling, since this comes with a lanyard and makes more sense safety wise.

Thank you for confirmation of this question....this forum is GREAT

(PS: Not sure the photos are going as planned)