Mercury 150 Won't Shut Off

IslanderVT

Seaman Apprentice
Joined
Mar 13, 2013
Messages
48
This isn't my boat, but hoping to help a friend with what sounds like a simple wiring problem on his ~1986 Mercury 150 O/B.

He is using older Mercury controls and had to manually connect the control wiring at the engine. Everything works fine, except he can't shut the motor down after it starts.

As I recall, there is a "kill switch" wire on these motors that needs to be grounded to shut it down. I assume its the same wire that would connect to a kill lanyard?

Anyone know how this kill switch is connected? Also if anyone has a schematic of this wiring, that would be super helpful!

(sorry if this is a dumb question...I don't usually mess with outboards!)
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,142
Re: Mercury 150 Won't Shut Off

A kill switch is for emergency use. The keyswitch should shut it off as well and is the normal method. Black/yellow wire is ign killer wire. With ign switch in off position it should be connected to black ground wire.
 
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