1989 Mercury 35 hp throttle control wiring NEED HELP!

[jalockwood]

Hello all, got a mercury 35 hp on a 1989 bass tracker pro 17 trying to figure out some wiring on the engine harness/ throttle control box. (engine serial number is 0a966049 and throttle control part number is 16900a15) The previous owner somehow managed to burn up the ground wire on the tachometer harness that comes out of the throttle control box and I was curious if I could just use a ground on my gauges ran back to my fuse panel? the power and ground for the fuse panel (interior and nav lights) are hooked to the same battery that the starter cables are connected to for spinning the engine over. Looks to me like if the engine harness grounds to the power head then I should be able to use a separate ground like im mentioning and it find a ground back through the negative starter cables. Also curious if anyone knows what these two wires go to on the engine harness as they are not hooked up. im going to post pics of what im trying to ask about and I hope what I said made sense, if theres any questions please feel free to ask so I can clear any confusion up I really need to get this figured out asap! thanks in advance!

 

[kofkorn]

Not certain, but the blue and green wires could be for Power Trim / Tilt All of the boats came wired for it.

Not sure how to help with the other wiring.

Good luck!