Mercruiser 120 ballast resistors?

[dezmond]

Hey everyone. Got a question for you all. What is the purpose of the ballast resistors on my engine? I know they drop the voltage for the stock cool but does it do anything else? I upgraded to the new electronic ignition and new coil so can I just unhook it? There is a tan wore that goes to the starter solonoid but I don't know why?

I have it unhooked and everything seems fine.

Let me know

Thanks,
Dezi

 

[bruceb58]

You still need it for the coil unless you change the coil to one that doesn't require the resistor.. The ignition module will get its power from before the resistor. Your install manual should specify this.

 

[dezmond]

New coil already installed new flamethrower 12v 3 ohm.

What is the tan wire that goes to the starter solonoid?

 

[acicomp]

Is the "tan" wire going to your negative post of the coil? It might be your wire for the shift interrupt switch. And yes, you can remove the resistor wire if you want to. Some people choose to leave it rolled up in case they need to go back to the points based system and have to reuse the old coil in an emergency. I just did the same ignition upgrade on my Mercruiser 120 as well.

 

[dezmond]

No. From the ballast down to the starter solonoid.

 

[bruceb58]

No. From the ballast down to the starter solonoid.

That wire bypasses the ballast wire while starting. You don't really need it anymore but it doesn't hurt to keep it. It goes to the positive side of the coil right?

 

[dezmond]

Yep it does. I will keep it tied off along with the old wire that went to the coil. I was able
To get my 12 volts from the white ignition wire for my coil. I was really impressed with the upgrade from points.