1976 Mercury 20 HP Stop Switch Wiring Help

[z27651]

I have a 20 HP motor that the stop switch is disconnected and I need help on how to wire it. I know the one wire goes to the ground and the other one goes to the control box some where but I can't figure out where. Serveral of the wires from the control box goes to the terminal block and there is one screw on the terminal block that is empty, is that where the other wire connects to? I spend last summer getting the motor to run and it is running great now, but I don't what to damage the control box by guessing where the wires go.

Thanks for the help,

Charles

[Laddies]

Here's a wiring diagram that should help 73 to 77 are the same.

[z27651]

Thank you very much for the picture, I installed the switch tonight and it works great.

[theclassicboatman]

I'm not sure if I'm posting this in the right place...but if someone out there can help me I'd be greatly appreciative. I've got a 1975 Merc 9.8-110 switch box that needs to be installed, but I cant seem to find a wiring diagram for this anywhere. It's a Mallory box if that helps; unfortunately the previous owner "already did the work" for me so there's nothing on the motor for me to go by. I could probably make a decent guess, but my fear is if I have something reversed (specifically the +/- leads to the coil) that it'll cause irreparable damage. If you could just point me in the right direction...

[Laddies]

First it's hard to get answers when you add on and ifnyou look at the 75 wiring diagram you will see the wiring is the same as the next few years model with the exception of the colors and I would expect a currenty part to have the new colors which meam you will have to use both diagrams to get it hooked up properly.

[onepingonly]

First it's hard to get answers when you add on and ifnyou look at the 75 wiring diagram you will see the wiring is the same as the next few years model with the exception of the colors and I would expect a currenty part to have the new colors which meam you will have to use both diagrams to get it hooked up properly.

Laddies, Thank you so much for posting those wiring diagrams. I've been looking for them for a while. I bought a 1974 merc110 9.8 knowing the stop switch wasn't wired....now I can do it.

[dangerdiver]

i have a 1970 mercury 20hp it had no stop switch and i need to wire one in - the button i have has two wires im new to outboards and i need a diagram please some one help me before i lose all my hair

[jimmystl]

Hi guys, new to the site but have found it very useful so far. I'm not 100% sure this will be posted in the correct place.

I see that someone posted a wiring diagram for a '76 Mercury Merc 200 20HP...i can't see to be able to see the diagram though?

I just picked up '76 20HP with electric start. I started digging into it last night. It looks like I'm going to need to replace the internal wiring harness. The majority of the smaller guage wires are very brittle and some actually broke. I took tons of photos last night as a reference in case i was unable to find documentation and/or a wiring harness.

All this being said, here's my question(s):

Can someone post a wiring diagram for that motor?
Where can I order the wiring harness. I'm having a hard time finding one. Universal???

Thanks a ton for any help