Positive wiring to coil gets too hot. Almost solved. Just need more info.

[Jadog]

Hello,
I recently just bought a 1986 4Winns 170 horizon. It has a 3.0l 140hp mercruiser. The purple resistance wire get too hot quick. When I disconnect the distributor positive wire, it fixes my problem. I have the engine wiring diagram but it doesn’t show any of the wires that my distributor has. Heres a diagram but this is not the distributor I have. There is also a yellow/orange wire on the other side of the dist wired to the engine block.

The coil is msd blaster 2. The distributor is the original. Should I try to start it without the positive distributor wire connect? I tried research it and usually there only a negative wire, but I have 4 wires from my distributor.

 

[Scott Danforth]

original distributor would be points distributor.

hence the purple resistor wire from the run feed and the purple/yellow wire going to the I/R terminal on the starter for the start feed.

so what ignition system do you really have?

 

[nola mike]

And the purple wire is supposed to get hot.

 

[Jadog]

original distributor would be points distributor.

hence the purple resistor wire from the run feed and the purple/yellow wire going to the I/R terminal on the starter for the start feed.

so what ignition system do you really have?

I don’t have any other system. No computer or module. Only msd blaster 2 coil and distributor sae j1171.

 

[Jadog]

And the purple wire is supposed to get hot.

I get that but it’s getting so hot it’s burning the wire

 

[nola mike]

I don’t have any other system. No computer or module. Only msd blaster 2 coil and distributor sae j1171.

That's not a distributor, that's your marine certification. What's underneath the distributor cap?

 

[Jadog]

That's not a distributor, that's your marine certification. What's underneath the distributor cap?

I apologize. This is my first boat. It does have a Mallory 6001m. Never checked under cap.

 

[Scott Danforth]

look under the cap.

most likely breaker points

if so, then service the breaker points, rough gap to 0.018, set dwell to 30-32 degrees

 

[Eric 3.7LX Alpha 1]

It has a module, so like a points conversion kit. If you have it wired like your diagram in Post 1, it is not correct.
Both the (+) terminal of the coil, and the red wire to the module, get powered through the resistance wire or ballast resistor.
Your diagram shows the red wire on the distributor module on the same terminal as the full battery voltage, so the module is getting full battery voltage.

Personally I would wire in the Mallory coil and distributor module with their own Mallory ballast resistor, PN 700, instead of the factory purple Mercruiser resistance wire, since it is their module. Keep all the components Mallory.

Here is the installation manual and wiring diagram for the Mallory set up.

https://documents.holley.com/mallory_module_pn_6100m.pdf