I recently got a Mercury 55 for my Achilles and I'm struggling to get the keyed ignition wired up as the wire colours I've got don't match any wiring diagram I can find online.
Anyone seen these before or have a matching set who can tell me what goes where?
Try putting your engine serial number into here
www.marineengine.com/parts/mariner-outboard/
You might have to pay a modest amount to buy the wiring diagram. It lloks like the terminals have letters on them which might relate to a drawing. Much better than trial and Boom error 
Hi es
It is interesting that the colours of your wires are the same as on a 7 pin trailer wiring harness
Is the wiring harness a factory part or is it something that someone has put together
Regards Don
Select to expand quoteDonk107 said..
Hi es
It is interesting that the colours of your wires are the same as on a 7 pin trailer wiring harness
Is the wiring harness a factory part or is it something that someone has put together
Regards Don
I believe it's a factory part, as when I stripped the outer cover on the main wiring loom that this small section plugs into I got the same wiring colors.
Turns out the reason I've been struggling so much looking for Mercury diagrams using these colours is that Mercury didn't make these motors, they are a re-badged Yamaha and Yamaha don't use standard wiring colours!
I'm also missing some parts - like the choke and cutoff switch - but now I know what I'm missing and why i should be home free.
