Mercruiser 3.0 L Ignition Conversion

[ranlj926]

I have a 1990 Mercruiser 3.0L and am installing a pertronix electronic ignition conversion and flamethrower coil. The old coil says it is for external resistor and pertronix calls for its removal but I do find anything that resembles what I know to be a resistor.

 

[Fishermark]

Re: Mercruiser 3.0 L Ignition Conversion

Welcome aboard!

The wire itself is a resistor wire. You can simply remove it from the coil and splice into the harness somewhere near the main plug to provide switched 12v. You might be able to splice into the wire that powers the electric choke. That is usually a good source.

 

[Fishermark]

Re: Mercruiser 3.0 L Ignition Conversion

By the way, if you go to the top of the page you can download the appropriate manual for your boat - it will include a wiring diagram.

 

[ranlj926]

Re: Mercruiser 3.0 L Ignition Conversion

There are two wires coming from the harness to the positive terminal on the coil, how do i know which one to eliminate?

 

[Fishermark]

Re: Mercruiser 3.0 L Ignition Conversion

This is on the positive side... one will come from the starter and will provide a full twelve volts while cranking. You want to keep that one and discard the other. You may need an ohm meter to trace the wires and see which is which. Did you look at the wiring diagram as mentioned above? I believe the colors will be purple, and the other purple with a yellow stripe. The purple with yellow stripe is the wire from the starter - that's the one to keep. The solid purple is the resistance wire.

 

[myoldboat2]

Re: Mercruiser 3.0 L Ignition Conversion

You can simply remove it from the coil and splice into the harness somewhere near the main plug to provide switched 12v.

That's how my pertronix on my Merc 140 is set up.