1978 Evinrude 140 tach hookup

[ntxf]

TAch wire was hooked to one of the wires on the ignition switch. When I removed the ignition switch to replace it, it popped off. ANy idea which wire it hooks to? This boat has been a wiring nightmare.

 

[Joe Reeves]

Re: 1978 Evinrude 140 tach hookup

What color is that wire?

Does that wire lead to the internal portion of the tachometer? If not, what is the terminal marked on the tachometer that the wire is attached to?

Normally the wire is purple in color and is attached to the "A" terminal of the igniiton switch. This allows 12v to be applied when the key is in the ON or START position to the tachometer voltage supply section and the light bulb if so equipped... BUT... it is best to be sure about where that wire is leading to on the tachometer and its coloring.

 

[ntxf]

Re: 1978 Evinrude 140 tach hookup

The wire is red and goes inside. The other wire I see goes into the harness.

 

[emdsapmgr]

Re: 1978 Evinrude 140 tach hookup

You may find the 1980 wiring diagram helpful till you can find one for your engine. It's in the "top secret" files, the first post at the top of page one of this Johnson/Evinrude thread. The grey wire in the control box is the tach signal wire. It does not get connected to the key switch.

 

[Joe Reeves]

Re: 1978 Evinrude 140 tach hookup

The wire is red and goes inside. The other wire I see goes into the harness.

There were some tachometers that had a "red" wire instead of a "purple" wire for the 12v supply to the tach. In all probability it should be attached to the "A" terminal of the ignition switch.

If after attaching the wire, the tachometer needle drops to zero when you turn the key switch to the ON position (engine NOT running), it is attached correctly.