Want to install tach but have an unusual outboard setup

[Pchrispy5]

I want to hook up a tach to my 1968 Mercury 650S. The brown tach signal wire doesn’t seem to bring anything up, and my outboard doesn’t have a stator or a rectifier. It was in that transition year that they had the kind of self running setup with or without a battery. I don’t know where the connection Point would be as the brown wire connects with the salmon wire in the connector, then only the salmon wire goes to the box. The box has a total of 5 connections, 6 if you include the body ground. 3 for the distributor (lightning energizer) and 2 go to the coil. Where would I hook a wire to for tach signal? I added an image of my wiring setup.

 

[Pchrispy5]

I have the right selection on the tach for the 12 pole, just not sure where to hook up. The salmon wire on the engine side hooks up to the blue distributor wire along with the engine’s mercury switch. Not sure what the distributor wires are supposed to be for as far as what does what.

 

[Pchrispy5]

Is it possible to hook up to one of the coil wires? It is hooked up to the coil on some car/inboard setups. Could I do the same here? Sorry I have this posted on another board as well and wanted to make sure all my questions got transferred.

 

[Pchrispy5]

Looking back i guess the pole selector will be decided later depending on the setup.

 

[racerone]

But the 12 pole refers to the number of pulses from a stator.----You say your motor does not have a stator ???

 

[Pchrispy5]

Yes thought about that after posting that part. Is it possible to hook up to the negative on the coil and I can find the setting later that would work for the tach. I have been trying to find some kinda specs on the original coil but have had no luck.

 

[flyingscott]

You need the old style tach

 

[Pchrispy5]

This is the coil. Pic 2 has the black wire on top and the white wire on bottom. Later versions had green instead of black, and black instead of white. I’m assuming my white wire is the negative. Does this coil work the same way as the 2 wire distributor coils on older cars or is the signaling different?

 

[Faztbullet]

Gotta have a stator to work

 

[Pchrispy5]

So I wanted to provide an update. I did find something I could use to send a tach signal. It is a controller that picks up the tach signal through an induction wire, then sends it at as a 3 wire rig going up to the tach. Now have access to my tach up at the dash. Just wanted to update for anyone looking at the same issue I had.

 

[guy48065]

I'm glad that worked out for you.
It doesn't make sense to me that dirt bikes & lawn mowers have a universe of add-on gauges & electronics but boats need to be this difficult?

 

[Pchrispy5]

I'm glad that worked out for you.
It doesn't make sense to me that dirt bikes & lawn mowers have a universe of add-on gauges & electronics but boats need to be this difficult?

I know, right?! This thing actually came from China too. Where all the obscure custom items come from.
Even did a custom cruise control on my hotfoot throttle, which of course the parts I needed came from China as well. Wanted to rid myself of the standard controls so I made use of 2 hands on the wheel while at the same time not wanting to lose functionality. Boat is finally almost done after about 15 months.

 

[The Force power]

So I wanted to provide an update. I did find something I could use to send a tach signal. It is a controller that picks up the tach signal through an induction wire, then sends it at as a 3 wire rig going up to the tach. Now have access to my tach up at the dash. Just wanted to update for anyone looking at the same issue I had.

And this works for any gauge?

 

[Pchrispy5]

And this works for any gauge?

It sends out a standard 4 pulse per rotation signal. Actually designed for cars, but worked out perfect for my needs. You do need to hook it up to the main ignition wire, not the cylinder 1 wire.

 

[guy48065]

Is this an Amazon item?