Wiring... don't you just love it.
Yamaha wiring is the same the world over. Yamaha have a specific tiller with the gear selector and kill switch integrated and should simply connect to your wiring loom on the engine. I sold a 40V (6H4) tiller that was like this as I was hooking up to remotes.
WHITE Wire - Engine Stop/Kill.
When this wire is earthed, it stops the engine. There may be more than one switch on tiller control models that connects to this wire.
For Example: The Engine Safety Kill Switch has one wire attached to earth and another attached to the WHITE Wire, Should you fall from the boat taking your Safety Lanyard with you, when the lanyard disconnects it either releases a switch to make contact or pulls a switch down to make contact. When this switch makes contact it connects this WHITE wire to earth which stops the engine.
BROWN Wire - Engine Start
When this wire is supplied with a positive charge it triggers the Starter Solenoid which in turn supplys 12 Volts to the Starter Motor to turn the engine over.
BLUE Wire - Engine Choke/Prime
When this wire is supplied with a positive charge it opens the valve on the Choke Enrichener or Creates a Electro-Magnetic field and engages the Mechanical choke mechanism.
PINK Wire - Warning System
This wire is connected to the Warning Horn, The warning horn has a constant 12V Feed from the purple wire (Ignition Live) whilst the engine is turned on, if a Temperature Switch or the Oil Level Sender makes contact due to the engine overheating, oil too low or simply a faulty sender the horn will sound.
YELLOW Wire - Ignition Live
This wire is the Ignition Live, it supplies 12Volts with the Ignition Switch in the On Position, it supplys the warning horn and dashboard gauges.
GREEN Wire - Tachometer Signal
This wire is the Sender (AC) For the Tachometer (Rev Counter)
Black Wire - Earth (Neutral)
This wire is Connected to the Engine Earth / Battery Negative.
RED Stripe Wire - 12V Positive
This wire is connected to the 12V Positive Supply from the battery
SKY BLUE Wire - TRIM UP Switch
This wire supplies positive to the Trim Relays when the Trim button is pressed up on the control box handle
LIGHT GREEN Wire - TRIM DOWN Switch
This wire supplies positive to the Trim Relays when the Trim button is pressed down on the control box handle