Jegs Mini Starter in 66 Wiring Question

[Steveoreno]

So I am installing a Jeg's mini starter on a 1966 327. I have it pretty well figured out with the exception of one wire....the pink one shown as "2". Originally the pink and yellow wires were bonded and I was directed to attach them to the " R Terminal" however there is no "R Terminal" on this starter. I learned that the yellow wire goes to the positive side of the coil and I have routed that and installed a diode at the coil. It was then secured to the opposing lug on the starter that provides power to the starter when the motor is turning over. The yellow wire will not be powered at any time other than when the motor is turning over. My question is...what is the pink wire? Clearly it is meant to be connected to a power source that is only hot when the ignition is in the "On" position so I cannot connect to the "BAT" terminal as I have done in the picture as it creates a parasitic drain on the battery....should I find a switched power source for it? What is its purpose? Thanks folks

[ray_mcavoy]

What type of ignition system are you using? Points or electronic?

The stock wiring had a pink wire running from the ignition switch "IGN" terminal to the firewall connector. From there, it connected to a special resistance wire that ran down to the "R" terminal on the starter solenoid. And then there was a yellow wire joined to that which ran up to the positive coil terminal.

With that system, the coil received power from the ignition switch through the resistance wire under normal running conditions. But when cranking the engine, the starter solenoid made a connection between the "BAT" and "R" terminals, bypassing the resistance wire and feeding full battery voltage to the coil.

With your harness having a pink wire (in place of the resistance wire) it appears as though it may be configured for HEI (or other electronic ignition system that operates off full battery voltage). If that's the case, and you're using such a system, the connection to the "R" terminal (if your solenoid even had one) would be redundant. So you could get away with just leaving that ring terminal disconnected and insulating it so it doesn't short to anything. Or neaten things up a bit and just splice the pink & yellow wires together and insulate the splice with some heat shrink tubing. This does assume that the ignition switch provides power to the coil in both the "run" and "start" positions ... most do, but if it only provides power in the "run" position, the "R" connection would still be needed.

If you are running a stock points ignition that needs the reduced voltage when running (and full voltage when cranking), you could use a relay to duplicate the action of the original starter solenoid's "R" terminal. And (since that harness doesn't appear to have a resistance wire) you'd also need to hook up an external ballast resistor somewhere inline with the pink wire.

[Steveoreno]

Ray, Thanks for the response. Well worded! I am running standard points. I installed a diode on the yellow wire that provides power to the positive side of the coil during cranking (as per Jeg's instructions). I connected it to the lug that becomes energized while the starter is turning over only and is without power otherwise. This morning I connected the pink wire to the same lug...energized only when the starter is turning over......not sure that is correct as it will have no power unless the starter is energized. I haven't tried to start the truck as yet so I don't know if this will work or not...it does turn over (working my way through the electrics now). The harness initially had the yellow and pink wires bonded to the same connector and were supposed to be connected to the "R" terminal. In standard form, does the "R" terminal provide power while the motor is running? that could be an issue if the pink wire needs to be energized in order for the motor to run......didn't think I would be opening a pandoras box when I went to this style of starter!

[ray_mcavoy]

You're welcome!

In standard form, the "R" terminal only provides power while cranking the engine. And when the engine is running, the pink wire receives power from the ignition switch, passes it through the resistance wire, to the "R" terminal (which just serves as a junction point), and then on to the + side of the coil.

As I mentioned earlier, a relay can be used to duplicate the function of the "R" terminal on solenoids that don't have one. Connecting the yellow wire to the to the starter lug that's energized while cranking (with a diode to prevent the ignition from trying to power the starter) is also another way to accomplish that.

That takes care of powering the coil when cranking. But you still need the pink wire to send power from the ignition switch to the coil once the engine starts and you release the key back to the "run" position. That means the end of the pink wire still needs to be joined to the yellow wire. And unless the new harness includes a stock type resistance wire, you'll also want a ballast resistor inline with the pink wire to prevent burning out the points and/or coil.

[Steveoreno]

Ray, Understood. I will get a 1.5 Ohm typical ballast resister and install it in the pink wire somewhere. This leads me to another question after reading your last response....having the yellow wire with the diode connected to the starter lug that is energized during cranking solves the problem of providing power to the coil during starting...and the pink wire provides power during running ...so if I have both the pink and yellow wires on the starter lug that is hot only during cranking...would the power being supplied by the pink wire cause the starter motor to try to turn over while the motor is running? I am just wondering if I should unwrap the harness, and redirect the pink wire to the positive side of the coil via the 1.5 Ohm resister and have the pink and yellow wires meet at the coil rather than the starter. Thoughts?

[ray_mcavoy]

Yes, having the pink wire unintentionally feed power to the starter is a concern. However, that's where the diode comes in to play. It acts as a one-way "check valve" so power can only flow from the starter to the coil, but not the other way around.

Don't bother opening up the harness to re-route the pink wire directly to the coil. Simply having it connected to the yellow wire (which then goes to the coil) will accomplish the same thing. Just be sure to have the diode connected between the starter lug and the pink/yellow wire junction. And (I'm sure the Jegs instructions already included this) but you'll want the diode oriented so the cathode (end with the stripe/band) is connected to the pink/yellow wire junction and the anode is connected to the starter lug that's powered when cranking.

Edit, on second thought, re-routing the pink wire up to the coil probably would make it easier to incorporate the ballast resistor. That'd allow you to mount it somewhere up near the coil vs. having it down near the starter.

[Steveoreno]

Ray, I opened up the harness to separate and re-route the pink wire to the coil and discovered that it is in fact a resistance wire as shown. It doubles back on itself a couple of times inside the wrappings with warnings not to cut it. I did cut off the large spade connector just to install a smaller spade that I assume (given that it is already a resistance wire) that I can connect to the + coil post without the ballast resister, and that is what I did (hope that this is correct...I ordered a ballast resister this morning so I am covered either way). Everything is re-wrapped and buttoned up. -Steve-

[ray_mcavoy]

Yes, with that pink wire being a resistance wire, there is no need to add a ballast resistor. So you're good to go with it hooked directly to the coil.

The warning about not cutting the resistance wire is meaning not to shorten it's length, which would reduce the overall resistance. The tiny amount you cut off when changing the terminal isn't enough to make any significant difference.