AguaSki
Chief Petty Officer
- Joined
- Jul 4, 2005
- Messages
- 545
I just purchased a new OMC tachometer off Ebay to replace my current tach. The wiring behind the dash still had the manufacture label that explained each of the wires by color.<br /><br />This is what I see on the manufacture label:<br /> Black = Ground<br /> Red = Ignition<br /> Blue = Lights<br /> Gray = Alternator<br /><br />My new tachometer has 4 threaded posts, but only 3 of the 4 are labeled.<br /><br />This is what I see on the back of the new OMC tachometer:<br /> "PUL"<br /> "+12V"<br /> "GND"<br /> There is an unlabeled post<br /><br />I am confident the black wire goes to the "GND" post, but need assistance in identifying the colored wire to attach to "+12V" and "PUL". I am guessing that the gray wire goes to "PUL", and the red wire to "+12V". Also, should the blue wire attach to the unlabeled post?<br /><br />This motor is a 1978 Johnson 140hp V4.