Interrupter switch

Hi all,
Looking for some wiring advise.
I have a Mercruicer leg with interrupter switch and a Chevy HEI distributor and am trying to find out how to connect them.
I understand the distributor isn't a marine unit but it was all working find before the engine was removed to rebuild and the electrical guy's I got to rewire didn't connect the switch back up.
I have read so many conflicting information.
I understand that with a seperate coil system you hook up the the negative and the other is ground and when the switch trips Stops spark for a split second to disingauge the gears.
How do I connect to the HEI.
I've read connect inline of the tachometer.
Do I connect to tacho wire or should I be connecting to one of the three pigtail wires ??
Thanks
Mike

 

The red wire is the + battery (B+), black is ground to coil and brown is the signal to coil (command). These three are bundled together. The two on the outside are the tach and the ignition (switched) wires. The ignition feed is usually labeled Bat.



This shows (below) the usual setup, without a tach wire.



I'm pretty sure you splice into the fat red wire, next to the tach.

A simple test is to start the engine and pull the red wire. If the engine dies, you got it.

 

Hi Par
So are you referring to the ignition (BAT) wire ?
Thanks,
Mike

 

Yep . . .

 

Hi all,
After some reading ive found out the standard chev HEI distributor isnt explosion proof as is needed in a boat.
I've had a look on the net and I'm thinking about the DUI marine distributor.*
From what I'm reading they have a HEI marine version.*
Does anyone have any knowledge about these ?
Is it has simple has removal of existing and installation of new ?
The existing is the standard chev HEI with positive ignition red wire and negative to the tachometer.*
The engine is a 350 Chevrolet vortex with a marine 4 barrel quadrajet.*
Has for the DUI am I going to have to run new or modify any wiring?*
As for initial and advanced adjustment is this done the same as the HEI ?
As for advance curve is the DUI adjustment done with different springs?*
A few questions here but I want to know if DUI marine is suitable for my application.
Thanks,*
Mike

 

That Davis distributor is a "plug and play" unit and accepts the stock "tack/bat" plug.

Marine distributors are a bit different than automotive, more than just a seal. There are conversion kits you can get, which are cheaper than a whole new plug zapper, but not by much. Most marine units have ball bearings, not bushings and a tighter cap clearance. Because it's sealed up (no cap vent) gases can build up inside and they in time, can cause cross firing, especially if pounded with a CD or ignition box, so they're built to much higher tolerances.

 

One good thing, the distributor is very high up, and gas fumes sink down.

Pertronix has one for $350, electronic, wires and coil complete.
http://www.ebay.com/itm/PerTronix-M...Wires-Chevy-305-350-5-7-427-454-/171948206210
Same but only $289
http://www.ebay.com/itm/PerTronix-M...Wires-Chevy-305-350-5-7-427-454-/151059006617

And this, I just saved you $300
http://www.ebay.com/itm/Mallory-YL6...-electronic-ignition-conversion-/301923569425