Dizzy wiring

Hey guys, just seeing if anyone knows if I need to use all four wires on my dizzy. The new ecu loom only has 2 x wires going to it a green and a purple. The old dizzy (scorcher) has 4 wires. An earth,power, sun and ref. Is it a matter of just using the power and negative or does it need the actual sun and ref as well even though the computer doesn’t use it?(does the actual dizzy require these to work?)

Thanks guys


Randy V

Lifetime Supporter
Post the make and model of your distributor. It sounds like an amplified hall effect. There should be at least one signal and one ground that need to be connected from those 4. The green and purple in your harness sounds reminiscent of the MSD unamplified pickup of their own distributor...
Hey mate, all I know is it’s a scorcher distributor with 4 wires coming from it. The wiring diagram for the old motel system says it’s :

A. Earth (black)
B. Ref (green)
C. Sync (blue)
D. Power (red)

I would like to just use the same distributor for the new system I’m running (speedmaster self learning ecu) but the new system only has the purple and green wires which from what I can gather is the mag pickup wires.
So is it just a matter of connecting the wires to 2 of the existing ones and if so which ones?

Thanks a bunch

Randy V

Lifetime Supporter
It looks to me like you need to connect all 4 in order for the distributor to work correctly.
The power line would need a connection to the ignition switch, earth to a local ground on the engine, then the remaining two wires woukd connect to your ECU.
Others may also chime in on this..