putting a new tach on boat for a 84 evinrude 70 hp , had a factory omc tach set at 6 but new tach has dip switches. the new tach is a nordskog that i'd bought from a marine surplus store. there are 3 dip switches on back they are labeled 1 2 3 on bottom and on the sides goes from 1-7. also trying to hook up omc trim gauge need help.
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