1972 starter wiring

[chip46wis]

Ok my 72 I now have has some butchered wiring I feel I can work around the added wiring for electric trailer brakes ect--this is coming off.
Here are my couple questions---from the left side of the wiring block coming through the firewall there is basically 3 wires running that direction towards starter--- purple 12? gauge and smaller red and green. I believe the purple is for the large lug for the battery (top) on the solenoid but which of these red/green? do I need to make it crank and run? on the small posts? I will be running a new HEI dist. Ok also where is a good place to get juice for the dist? THANK YOU!!!!!!!

[fleetsidelarry]

the purple goes to the "S" post on the solenoid NOT the big lug (battery power). the purple comes from the ignition switch (and neutral safety if so equipped) and is only energized when the key is in "start" position. it is what triggers the solenoid to activate the starter.
Since you are going to run an HEI you shouldn't need any other wires to the starter since it is no longer necessary to use the "R" post for ignition (if you power your HEI via a wire to another switch-on source as is typical).

I don't know where the green and red wires go back to under the dash. if you can trace them back, we can figure out if they are needed and where to put them. on my wiring diagrams there are no oem red and green running to the starter but I don't have a '72 diagram

[chip46wis]

Cool!!! following your advice and going through a wiring diagram SEVERAL times you are totally correct--- I thank you so very much----Chip And may I ask where is a good place to get the 12v needed for the HEI?

[fleetsidelarry]

there should be a key-switch-on terminal on the fuse block. that's where I did mine and I think most peeps do also. easy to find if you have a test light (if you have occasion to play with your vehicle's wiring a test light is an extremely handy thing) you don't want a constant-on (direct from battery) source.

you probably could use the ignition-out from your ignition switch since it will no longer be needed to operate the coil BUT you'll have to make sure you bypass the original resistor wire (I assume they still used one in '72).

[VetteVet]

Larry is absolutely correct and here are some diagrams.

This is the stock wiring used on most all the years from early 60s to early 70s including the 72.

The stock factory wiring showing the starter wiring and the stock points coil with the resistance wire. The yellow wire is for the starting cycle to give the coil a full 12 volts for starting. After ignition and engine running it drops out and the ignition voltage runs through the resistance wire to fire the coil during normal operation. This is to protect the coil from over voltage burnout.



Here's the resistance wire from the fire wall connector. This is a very good place to run the HEI distributor power from, since it comes directly from the key just like stock. It requires removing the stock resistor wire from the block and installing a new wire from the block to the distributor.




This is a picture of the actual wire in the block. It started as a white orange purple wire but over time it gets to looking like a cloth covered white wire like in the picture. The large purple wire next to it is the solenoid S terminal wire.
I believe the red and green wires on the starter were just power wires to some other devices.




Here is the diagram with the HEI wire installed.

[fleetsidelarry]

good stuff there, VetteVet.

[chip46wis]

WOW! all of you are just incredible!!!!!!! Diagrams even! THANK YOU!

[VetteVet]

Hey! I'm not just another pretty face you know!!!!!!

[chip46wis]

Maybe not another pretty face but a good trucking buddy---Thank you!

[dirtyjim]

the best thing to do with the hei is to just buy the new lead wire from orange county truck shop. pn 60-132046. its $6 whole dollars, made by m&h, has the correct Packard 56 terminal on one end and the hei plug on the other. I can barely make one for that price and I have the terminals, wire and crimper.