wiring a tach, 1978 115 Johnson V4

[old islander]

Does anyone have a wiring diagram to add a tach to a 78 V4 Johnson. The boat and motor I have never had one, but I need one for prop testing.
Thanks, Old Islander

 

[boobie]

A local BRP dealer may have one in his collection of instruction sheets.

 

[metriccrescentwrench]

http://forums.iboats.com/forum/engi...and-evinrude-s-many-years-and-models?t=515631

I don't think your exact engine is listed, but here's one that should be close:

http://maxrules.com/graphics/omc/wiring/80_81_V4.jpg

On that you'll see the grey/yellow wire coming from the stator to the rectifier. On the terminal block there's a grey wire connected to the grey/yellow one, that grey wire is the tach signal. The other connections to the tach will be + and -.

 

[emdsapmgr]

Wire the tach for power and ground to the other dash gauges. The tach signal wire is inside the factory control box. OMC left that grey wire there, cut off, when the control box was originally manufactured. Open up the control box, and pull the stub end of that grey wire down through the factory hole- drilled between the two control box halves on the bottom/under side. Splice that wire to another wire and connect to the dash tach. Set the Marine tach to position #6.