Kill Switch

I have a Mercury 50 HP 2 Stroke that has had an external Kill Switch fitted to it at some time. The Control Box is a Quicksilver type.

I thought it worked when I bought the boat, but have since found out that it has no effect whatsoever on killing the engine when the Kill Cord is pulled.

The engine runs fine and can be stopped with the key.

On looking at the wiring for the Kill Switch, I can see three wires.

One Black wire is moulded directly in to the bottom of the switch.

A Black and Yellow wire is also moulded directly in to the switch.

A third wire, also Black and Yellow and contained in the same protective sleeve as the other two wires is not connected to anything.

It does look as though possibly the loose Black and Yellow wire was connected in to the base of the Kill Switch and may have broken off some time ago, but I am not too sure about this as it would need to go in to the base of the plug very close to the other Black and Yellow wire.

Could it be that the loose Black and Yellow wire goes to earth or does it goe in to that switch. I suppose it would make sense for it to go in to the switch.

Any Help would be appreciated.

Kill switch works by making the black and yellow wire to earth.
(Not looked inside a control box for a while as we don't use them on the race boat) the broken wire is probably the kill wire and the black and yellow still attached is a spare for running to another kill switch.
Try earthing the free black and yellow whilst the engine is running, if it stops the you have your answer.

Hi Kitten

I tried touching that spare yellow and black to the switch today and got a massive shock. I came over all sort of queer. Ooh Aar.

Any more testing showed me that the spare wire definately goes to the switch. Its out with the soldering iron this weekend.