We are rewiring our OMC cobra and trying to fix a very sloppy job done when an "86 tilt/trim was put in a "90. We have added the second selinoid which was left off but now we are unsure which of the three wires coming from the tilt/trim is the ground.... blue/black/green??? Wiring diagram in OMC book shows blue but with the way things have been wired..........can't trust that. Can anyone help???