Originally Posted by bcfryer
How the neutral switch works is.......when you turn the key to the start/crank position, 12v is sent out of the brown wire from the key switch harness into the main engine harness thru the brown wire. That connects to the harness for the binnacle control. The brown wire is connected to the neutral safety switch in the control. If the switch is closed(neutral) that 12v will flow thru the switch, back to the main engine harness and back to the engine. It will then activate the starter relay and the motor should crank.
If the switch is open(in either gear) the power can not go thru the switch, therefore the engine will not crank. To test the neutral switch, disconnect the 2 brown leads that go into the control, and on the engine harness side, connect them together. You have bypassed the switch this way. If you still have a problem, the switch is not the problem.
Link to the older style switch for that 2003 control. http://www.simyamaha.com/product_p/704-82540-00-00.htm