I have a '77 Glastron HP154 with a '75 Evinrude 70hp. I bought this boat last summer and have taken it out a couple of times. The tach has not worked since I have had the boat. After searching old posts on here I finally figured out that the tach was hooked up incorrectly by a previous owner. The signal wire coming out of the tach was not even hooked up and the 12v wire was hooked up to the signal wire coming out of the engine. I corrected the wiring and now the tach needle zeroes out like it is supposed to but it still does not register any rpms. I ran a wire from the signal wire at the engine directly to the tach and it still did not work. I checked the signal wire with a voltmeter with the engine running and there is voltage on that wire. Also, I checked the voltage of the battery with the engine running and it showed over 14 volts, so I know the charging system is working. I have concluded that the tach is bad. What kind of tach do you all recommend for this engine? The hole in the instrument panel is 3 3/8". Thanks.
