Yamaha Key Switch question

[Who's your daddy]

Recently had an issue with 2 of my 2006 Yamaha F250s turning over fine but not starting. Checked everything , no filters, etc and they still wouldn't start. Had a guy ask me if I happened to check the key switch for issues. I unscrewed the key switch panel and exposed the wires. I wiggled the wiring harness and wires that are attached to the key switches that were giving me trouble. After that I attempted to start the motors and they fired right up. Also the key switch sounded the buzzer as I was turning the key to start. Now it doesn't sound the buzzer as bad , but there is a faint sound of the buzzer.

Question is, whaif anything is in the wiring of the key switches that would keep the motors from starting? Like I said earlier, they turned over fine before but just didn't start. But after wiggling wires around, they started right up.

Ideas?

[panasonic]

Sir I am not trying to be a smart a-- but you have a loose/corroded connection there..

It may be the wires or connectors going to the key switch. Or loose/corroded conections in the key switch itself..

Are they individual wires with spade connectors plugged on the back of the key switch? Or is a plug connection to thekey switch?

You may want to do some further investigation in that area and see if you can find the problem....before you get stranded somewhere. Take a few pics before you start disconnecting stuff.

[Jason2tpa]

Every time I've had to wiggle wires in order for a circuit to function is because of a bad ground. Might want to start there.

[Who's your daddy]

Thanks guys, I will check connections and ground. Just kind of strange that the key switch would control the motor turning over fine but not starting up.

[boscoe99]

Thanks guys, I will check connections and ground. Just kind of strange that the key switch would control the motor turning over fine but not starting up.

The key switch has two three main functions.

When turned to the off position it closes a stop switch to stop the motor from running.

When turned to the on position it opens the stop switch while at the same time closing a run switch. The run switch applies battery power to the motor for numerous components such as the ignition coils, the fuel injectors, relays, and whatnot.

When turned to the start position the run switch stays closed while a start switch also closes. The start switch applies battery power to a starter relay, to make the starter motor crank the engine.

When the key is turned back to the run position the start switch opens while the run switch stays closed.

When the key is turned to the off position the run switch opens and the stop switch is closed.

Graphically it can be seen below. Perhaps the key switch is not opening the stop switch while the key switch is in the run or start position. If the stop switch is closed then normally the buzzer will sound if and when the key is in the start position.

[Who's your daddy]

That's what I was looking for ...... thanks everyone for the help.

[Jimbangle]

Won't turn off

My 9.9 won't turn off. I have changed the ignition switch and tested the white wire from the control box right back to where it disappears at the motor.
I tried unplugging the kill switch as well.
Can a defective kill switch cause the motor to keep running even if the ignition key is off ?
Can the problem be in the CDI ?

[99yam40]

key switch and kill switch ground the white wire to stop the spark voltage.

You really need to start your own thread