Lucas Ignition Switch - Brown Yellow Wire - Perkins 4236

[Deleted member 36384]

My boat is fitted with an old style Lucas ignition switch, turn to power up, turn against spring to heat, turn further against spring to power starter solenoid. I had to fiddle with the switch after 2 1/2 years lay up and noticed that a brown with yellow strip wire was not connected. There are two spare male spades on the switch, a large one and a smaller one that fits the brown / yellow spade connector. The male spade on the switch is a double spade and also has a large diameter white wire connected to it. The engine runs fine without the brown / yellow wire connected but I am wondering what it is for. There is an old push to start spring button on the throttle console which has been decommission many years ago and is not used, I wonder if that is what it was for? Any ideas?

 

[David2452]

If it's been added to then it's anybody' guess but white insulators in extra low voltage DC marine usage are usually reserved for alarm functions and manual override on bilge systems. Why not physically trace the white cable and see where it goes.

 

[Deleted member 36384]

Its not the white cable, that is connected and is a large spade, the brown/yellow is the wire I am wondering about and the only space for it is on a smaller spade terminal shared with the white wire. The wiring loom looks original as do the wires. I have never used the heat start function which I think is a device at the air inlet (fuel line and electric device terminate just inside the air inlet), so it may be for that, which is why its never been missed. The engine is great starter, just fires up nearly instantly. But yes, I could trace it.