My gdsd would not crank by key and i changed the ignition switch and solenoid and still did not crank. well, it was the mercury switch that black tube with two wires coming out one end. I by passed it and hooked the yellow wire in its place that how vangaurd does it from factory and that baby fired right up.
A couple guys on here had this problem and may this might help out with that
GD puts that switch on themselves so this may not be a factor in other motors.

If anybodys needs pics for instructions let me know

Hey i would like to see some pics on how you did this if you dont mind. you can send them to tsutxn09@yahoo.com if you dont want to post them on here

If GD is putting it on there, do you know why? I would speculate its for safety but don't know. Maybe OK to bypass to get going but should you replace it?

GD puts that on there so that it forces you to start the motor in the neutral (prop out of water) position. The other manufacturers have neutral, GD doesn't. That way you can't start the motor while the prop is in the water and instantly start moving forward.