Been searching around but could not find a answer that helped me.

I took the battery out of my 97 seadoo speedster earlier in the summer and when i just recently went to put a new battery back in its place I ran into a snag. There is one black wire, 1 red wire, and 1 wire that looks like it is dark purple. I will retrace the purple one again but I think it went into the MPEM. The black wire is grounded on the boat and the red wire also goes in the MPEM. Which post do i hook the dark purplish wire to? I didnt want to hook it up wrong and fry any electronics.

Any help would be greatly appreciated.