Mini starter gets the purple, and Batt.
The purple is your start circut from your ignition switch (tells your starter to start)
The Batt supplies the starter with power to operate only.
The yellow wire is the topic of many posting in this forum, (do a search), but just to try and explain, read on.
In SOME cars the ignition switch does not provide power to the coil during the start mode, only in the run mode
Therefore, the coil needs power when you are cranking. The yellow wire was designed to go to the I terminal of the stock 3 lug starter and feed your coil with 12v. during cranking only.
The question is do you need that yellow circut. Check to see if your ignition switch is supplying power to your coil when the the key is in start and run if it is then you don't need to connect the yellow wire, tape it into the harness and you are done.
If your ignition switch does not give you power in start (like it did in my 67) then you have to get it power.
There are 3 fixes that I know of (and many that I don't Know)
1. Change Ignition Switch ( to a later year if possible)
2. Get a starter with 3 wire hook up
3. Use a Ford style remote solonoid, this will give you the I terminal for your yellow wire.
I chose #3 with my car because I needed the 2 lug mini starter for header and oil pan clearance. And It works great
Hope this helps, Rob
67 Malibu Conv (always under construction)