Corect Part please

[mr steve wayne]

My project boat is a 1984 Sea Ray with a Mercruiser 260 engine. I ordered a new coil and points for the electrical system from NAPA auto parts. The coil is made by Sierra Company, and is part number 18-5438. It says on the box “Replaces Mercruiser 392-7803A4”.
It says on the coil the following: “use with external resistor” then below it says “Use of resistor required if used on Non-Thunderbolt Ignition system”
My question is how can I tell which ignition system I have, and where is this External Resistor they are talking about?
Thank you in advance for your comments

[mmwjr]

Being that you have a points and condenser ignition system it’s not the Mercruiser Thunderbolt which is an electronic ignition system.

[mr steve wayne]

So is it a good idea to replace the resistor also?
And also where would it be mounted?

[mmwjr]

Originally Posted by mr steve wayne

So is it a good idea to replace the resistor also?
And also where would it be mounted?

Can’t help you on where it’s mounted as your boat has been modified based on your previous post. This boat was originally equipped with the Mercruiser Thunderbolt IV ignition system but now has a points distributor.