markmcintyre
New member
I have bought a 50hp Thunderbolt 4 cyl twin carb (mid to late 70s model i think) and the "MerControl" control box wiring is all coroded. My old motor's (40hp mid 70s thunderbolt 2cyl single carb) "Quicksilver" control box is good. however the 50 has a female plug base and the 40 has a male plug base so i want to splice the old control box with the new plug. The problem is that the colour of the wires are different. I need to know what each wire does if you can help please and thankyou.
The ones in red writing are the ones i am unsure of.
50hp (female plug) wire colours:-
Red : +
Black: -
White: Ground?
Yellow: Neutral Start Switch.
Orange: Cut off power to motor / Mercury switch?
Grey: Choke solenoid.
Brown: Tacho
40hp (male plug) wire colours:-
red: +
black: -
grey: ?
yellow/black stripe: ?
yellow/red stripe: ?
black/yellow stripe: ?
purple: ?
tan (or very light brown): ?
The ones in red writing are the ones i am unsure of.
50hp (female plug) wire colours:-
Red : +
Black: -
White: Ground?
Yellow: Neutral Start Switch.
Orange: Cut off power to motor / Mercury switch?
Grey: Choke solenoid.
Brown: Tacho
40hp (male plug) wire colours:-
red: +
black: -
grey: ?
yellow/black stripe: ?
yellow/red stripe: ?
black/yellow stripe: ?
purple: ?
tan (or very light brown): ?
