Would anyone know how to wire a model 690 Airguide Sea Speed Tach? Attached please find a number of pictures with the paperwork that came with this unused unit! My motor is a 1960 Evinrude Lark II 40; magneto. Reading through all the pieces, for two cylinder 2-strokes it says that no jumper wire is needed on the back of the tach – so I’ll remove the jumper wires that are there now. Some of these old Airguide tachs have separate sending units, but this one seems to have it built in. That leaves two wires coming out of the back of the tach; the yellow one and the black one. In the paperwork, there is a paragraph that explains how to hook up the wires; although it is not for the same motor as mine; it is paperwork for the electric shift/electromatic/selectric controls; I have an old Gale unit which is not electric. It says to connect the black wire to a good electrical ground; I can run it straight to my fusebox which has a negative bus panel; that should be the same instruction regardless of the type of motor, I would think. The yellow wire is the question. The paperwork says to connect the yellow tachometer lead to the ‘solid gray wire in the electrical portion of the control box. I don’t have a gray wire there, but assume its unique to the electric shift models. I do need to get a signal from the magneto for the tach to work, so I’m thinking the only choice I really have then is one of the black ignition wire posts marked ‘M’ on the back of the ignition switch? I imagine it wouldnt matter which one. If anyone has any advice on this, I would appreciate it. Thanks very much!
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