Re: 93 Yamaha 150hp Tach Issues
check the tach signal at the tach with a digital multimeter set on the AC scale. the tach signal lead is the dark green lead coming from the 10 pin main ign harness(704 box) or the dark green wire coming out of the 703 (sidemount) harness.
make sure its plugged into the dark green lead at the tach.
pay no attention to the all fits from the above poster ospreyangineer as they all simply dont.
command link wont fit any carbed 2 strokes.
but there are the last 3 versions of the digital multifunction tach and some are incompatible with motors older than 01.
the information can be found in the 05 and 06/07 marine technical guide.
when you find the tach lead attach one meter lead to the dark green and the other to the black.
with an adequate supply of cooling water start the engine and observe the voltage, raise the rpm 1000 or so and reobserve the voltage it should have risen a few volts.
your engine is old enough I cannot remember where to tap into the tach signal at the engine.
but yes the parts girl was correct.
not all digital tachs for 2 stroke motors are comptible with engines from 84 to 2009.
command link is only compatible with the 05/06 and up EFI 4 strokes and the Z 250 and z300 motors. but command link is command link and not considered a digital multi function gauge.
if you have a tach signal voltge you may have bad meter.
its also possible you plugged something up wrong.
