Best place to tap for Electronic ignition

[Condor1970]

The manual for my new Pertronix Ignition system states to tap the coil right off the start switch. I really don't want to run a wire all the way to the dash. What do you guys think is the best spot on the engine to tap off for a new coil, instead of using the existing wire which I believe is a resistor wire?

 

[Bt Doctur]

Not knowing what your working on ,but I`ll guess the electric choke hot lead is a full 12v

 

[thumpar]

When I did my 2.5l I opened up the harness and run a new wire alongside the resistance wire. It is not the easiest way to do it but was clean. Most people just tap into the choke.

 

[Condor1970]

Oops, sorry. It's a 1989 Mercruiser 3.0L.

 

[stonyloam]

On mine, at the recommendation of my electrical guy, I ran a wire to my electric choke wire that activates a (electric fuel pump) relay that then supplies 12v directly from the hot side of my slave solenoid to the coil +. When the ignition is turned to on, the relay closes and feeds a full 12v to the coil. The run is short and the wire is large, assuring plenty of juice for the coil. Maybe overkill, but works fine.

 

[Condor1970]

As I look at the wiring diagram for my engine, I can see how the resistor wire is basically spliced off the choke wire to begin with. So, it makes sense for me to simply disconnect the resistor wire on the coil, and run a good sized line backtracking from the choke to the ignition coil.

 

[stonyloam]

As I look at the wiring diagram for my engine, I can see how the resistor wire is basically spliced off the choke wire to begin with. So, I makes sense for me to simply disconnect the resistor wire on the coil, and run a good sized line backtracking from the choke to the ignition coil.

That will work just fine.

 

[pureinsanity]

On mine, at the recommendation of my electrical guy, I ran a wire to my electric choke wire that activates a (electric fuel pump) relay that then supplies 12v directly from the hot side of my slave solenoid to the coil +. When the ignition is turned to on, the relay closes and feeds a full 12v to the coil. The run is short and the wire is large, assuring plenty of juice for the coil. Maybe overkill, but works fine.

This is basically how I just wired mine in. With the splice off the choke wire just being a signal to the relay, it's not robbing any juice form the choke. And I know the coil is getting a good full 12v when triggered. I also put a fuse in the circuit for good measure.