from the factory, the starters had an R circuit (minus 61-63 models which had it built into the ignition switch.) to aid in easier starting, the R circuit on the starter was supplied with power during cranking, to bypass the ballast resistor and supply the coil with a full 12 volts. otherwise, while the car is running, the ballast resistor cut voltage to the points, to keep them from quickly burning up. with most hei and electronic pickup conversions (not all), they require a full 12 volts at all times. this can be achieved by simply hooking all the wires together at the resistor on the firewall on 50s cars, and/or bypassing the special resistor wire from the ignition switch to firewall on the 60s cars. the terminals can be jumped at the ignition switch on 61-63 cars, to supply coil with 12 volts all the time. with units like the 1181LS pertronix, you can actually leave the stock resistor wire and run a lower ohms resistance coil (.6 ohms) rather than the stock 1.5 ohms coil. this is not a solution for every pertronix unit, however. removing the resistor wire itself, which is a skinny, clear housing wire, its not super easy to change. you will need a special tool to pop the connector from the housing and new wire, must be soldered on to the old connector. any bulky butt connector will not fit into the back of the ignition switch housing! always read the instructions that come with your unit and follow them. don't assume the the directions are the same as your other car that you put pertronix on.
because all the mini starters are retrofitted later application modern starters, there's no R circuit on any of them. if you're already running an electronic conversion or distributor such as MSD, theres no reason for the R circuit, as the distributor is already getting a full 12 volts. simply tape off your R circuit wire which is always yellow on the stock cars. on these cars that are still equipped with original points ignition (which by the way, there's nothing wrong with running.) that's where the special pig tail we sell, comes into play. the purpose of the pigtail is to do the same thing as the original R circuit on the starter. black wire goes to your purple R circuit lead (cranking power). plastic connector pops into your S circuit spade on starter solenoid. the red wire with built in diode, goes to positive side of the coil. this gives the coil a full 12 volts during cranking. the built in diode is essentially a 1 way door that keeps power from going the opposite direction and engaging the starter while the engine is running. please see wiring diagram below. of course if you have any questions regarding install of any parts you purchased from me, don't hesitate to shoot me a call