Johson 87 150 Tachometer malfunction

[strombolichef]

I am just beginning to get to know a proline 20 cc with a 1988 Johnson 150 GT. There is a standard OMC tach plus a larger size fancy one on the dashboard. Of course the inside of the dashboard looks like spaghetti to me at this point of my relationship with this old boat.

full speed the OMC tach is showing something like 2500 rpm.....What are the steps to troubleshoot this?

The other tach is dead not doing anything.

Thanks for your assistance.

 

[HighTrim]

Re: Johson 87 150 Tachometer malfunction

This should help. Let us know what you find. Good luck.

Connections required are: Ground, 12 vdc (switched on/off from Ignition/Start Switch), AC (alternating current) from alternator (usually a Gray wire in engine harness, see schematic below).

If lighting is desired, 12 vdc from Panel light Switch.

 

[DJ]

Re: Johson 87 150 Tachometer malfunction

On the back of the tach. there is a switch. Make sure it is set on position 6.