Re: Tach Problem
There are only three connections that the tach requires. If all you did was "look" at them, this is not a valid check. Intermittents are almost always due to bad connections. Disconnect, clean, and reinstall the connections on the tach. Then go to the other end of the harness and repeat the process. If the tach connection just below the ignition key on the side mount control box is used, ensure it is clean and tight. Next, using a voltmeter, ensure you have +12 volts on the "I" terminal of the tach. Then using the ohmmeter function, verify that the ground connection is ok. Lastly, start the engine and verify that you have "some" voltage on the "S" (sense) line on the tach. This is the signal from the engines charging system. If any of those connections or signals are bad the tach won't work. If they check out, then the tach is probably bad.