90 HP tilt trim wiring harness compatibility

[mhtuba]

I recently acquired a 1982 Johnson 90. The tilt trim wiring was pretty beat. I bought a much better condition 1981 harness from Ebay - very different - One replay instead of two, and three lead going back to the unit's motor instead of two.
Does anyone out there have any experience with this? It seems simple enough; it looks like OMC went to two replays - one for the positive and one for the negative after this unit was made in 1981. The polarity reversing is the same at the throttle switch.

I'm wondering what to do with the "extra" wire going to the motor unit - there are two blue wires and one black. The wires from the engine itself are blue and black.

Any thoughts?

Thanks!

[boats.net]

Trim motor should have a green wire and a blue wire, one to each relay, trim switch will blue, green and red wire, red is 12 volts to switch, blue is up wire to relay and green is down wire to relay.