Tachometer wire in Control Box

[haycord]

It is a 1986 Johnson 150 Hp with Johnson Control Box. The tach moves up to zero when key is on but does not display RPM. There is no continuity between the D-shaped plug on the Control Box and the Send Terminal on the tach. How do I open the Control Box, and will "springs and balls" fall out? Second question: The gray wire goes to a black terminal strip (No.3) on side of engine. Two other wires also land there, a gray to the VRO and a gray goes under a metal plate (3x4) under the rear of the flywheel. What is under that metal plate? Best regards...

 

[V156]

Re: Tachometer wire in Control Box

Is the tach harness loose? If your getting power to the tach that solves one problem. Check the wires on the back of the tach and see if they're loose or covered with gunk. Also check to see if the wires on the motor are tight or gunked up. If everything is fine your retifier could be bad. Do a search here to find how to check it.<br /><br />Dutch

 

[haycord]

Re: Tachometer wire in Control Box

Thanks, but the problem is in the Control Box. There is no electrical path from the D-shaped plug (gray wire) to the tach Send Terminal. From the D-shaped plug to the engine is fine.<br /><br />I will tear into the Control Box but I wanted to first see if someone who "has been there" might give a few pointers. I suspect a broken wire inside the Control Box. Best regards...