79 Evinrude won't shut off with key

[nvanzee]

I have I believe a 79 Evinrude 25hp. Worked fine last fall. Now doesn't shut off with the key. Have to choke it to get it to stall. I replaced the ignition switch but that didnt fix it. I checked both wires labeled M at the ignition. Both are grounded with key on or off. Have continuity between them only with key off. I have a good ground on the motor and the outboard housing itself. Don't know much about outboards. Anyone have any suggestions on what to check next?

 

[oldboat1]

might help: https://www.maxrules.com/graphics/omc/wiring/1973-76_18-25.jpg

 

[Vic.S]

might help: https://www.maxrules.com/graphics/omc/wiring/1973-76_18-25.jpg

I don't think it will. The 1973 to 1976 models have points ignition
A 1979 model has cdi ignition

This diagram for 25-35hp 1982/83 models will be more like it

https://maxrules.com/graphics/omc/wiring/25_35_82-83_elec-remote.jpg

Check the continuity of the two wires on the "M" terminals of the switch
One ( black, ? ) should show continuity all the way to the motor ground.
The other ( black/yellow ?) should have continuity to the Cdi unit.

There may be a bad connection through one of the multi-pin connectors.

 

[nvanzee]

I don't think it will. The 1973 to 1976 models have points ignition
A 1979 model has cdi ignition

This diagram for 25-35hp 1982/83 models will be more like it

https://maxrules.com/graphics/omc/wiring/25_35_82-83_elec-remote.jpg

Check the continuity of the two wires on the "M" terminals of the switch
One ( black, ? ) should show continuity all the way to the motor ground.
The other ( black/yellow ?) should have continuity to the Cdi unit.

There may be a bad connection through one of the multi-pin connectors.

Thanks. I ended up finding a spot in the harness that had rubbed through

 

[Vic.S]

Thanks. I ended up finding a spot in the harness that had rubbed through

Thanks for reporting back.