79 mercury 90hp Motor won't turn off with key

[theprophet1985]

Well I just replaced my wiring harness on my 1979 Mercury 90hp motor.
It was supposed to be the direct replacement according to Mercury.
So I just got done with everything and went to start her up. Which might I say ran great well when I tried to turn the key off she just kept going.

The wiring harness that I received was the same with everything EXCEPT the addition of 2/3 wires 2 white/red and 1 white which were no were to be found on my old harness OR my seloc manual that leads from the harness plug.

A little more info. I replaced the wiring harness MOTOR side not BOAT side.


A question I might have to ask. Is there supposed to be a wire from the Stator to the rectifier. As it might act as the kill switch?
If any one is familar I would highly appreaciate any and ALL assitance

 

[Chris1956]

Re: 79 mercury 90hp Motor won't turn off with key

1979 motors can be unique.

Does that motor have a distributor? If so, the orange wire on the motor is unused, and the white wire from the harness needs to be connected to the white terminal next to the red terminal on the switchbox.

If you have the two switchbox non-distributor ignition, the orange wire need to be connected to the switchboxes to kill the spark. Look on the Maxrules.com website for a wiring diaghram.

 

[nathanhooper]

Re: 79 mercury 90hp Motor won't turn off with key

My 79 90hp has the switch boxes. I am a cheap guy, so I rewired my wiring myself instead of buying it. It was helpful because it forced me to know what each wire is for. I did not know what they were for before I began, but there is the "orange" wire that has three taps off of it. One goes to the mercury switch, and one to each switchbox. I thought before that they were for "charging" the system, but then when you think about it the mercury switch is used for cutting off the engine, or not allowing it to start when tilted up.

It helps to have a visual reference, so here you go.