HEI Distributor/Starter Issue

MNMustang73 · Nov 24, 2018

I have been battling my starter/wiring for quite some time and I am fairly confident that I have some wiring that is wrong as a result of an HEI conversion. My starter engages on RUN and obviously will not disengage once started. I tried to stick to the factory wiring schematics because I have no idea how it was connected by the previous owner and obviously, this isn't working.

The car has a GM HEI Distributor on the 351c (It came installed when I purchased the car). My issue is that I get 12 volts at my "S" terminal as soon as I turn the key to RUN and when the car starts, I have constant voltage going to my starter keeping it engaged. The wires that I used to hook everything back up on the starter solenoid are the factory red with a light green line on the "S" terminal and the factory red with a light blue line on the "I" terminal. I have a black with white wire feeding the electric choke. In addition, I have no wire to feed the tach from the distributor which I am assuming needs to be a new wire?

If it matters, I have tested the solenoid and it is good. I have also replaced the ignition switch to correct a previous issue. I also have an ignition cylinder on order.

Can someone provide me some detailed advice on how to correct this issue and get everything working properly.

clevelandcoupe · Nov 24, 2018

I'm sorry to say that it is your Mustang telling you to get rid of those GM parts........

Thanks, Jay

LeglessOne · Nov 24, 2018

Pretty sure you have the "s" and "i" wires around the wrong way.

Red with light blue should pull the solenoid in when key is in start position and the red with green wire is fed 12 volts during this from the "I" post on the solenoid.

Shane

TheRktmn · Nov 24, 2018

Solenoid S post is the start circuit. This wire is BLACK w/ ORANGE RED w/ Blue tracer. It should only be hot when the key is in the start position.

Solenoid I post is the ignition hot start wire. It bypasses the pink ballast wire and provides full battery voltage during start. This wire is RED w/ BLUE RED w/ GREEN trace. It will have voltage in the run position, but only what is back fed from the primary circuit to the coil.

Your (factory) tachometer goes between the ignition switch key and the coil + side, or in your case the BAT connector on the HEI cap.

EDIT:

According to the '73 diagram the S wire is Red w/ Blue and the I wire is Red w/ Green.

You can verify by 'ohming out' the wire from coil + to the I post.

The electric choke is White w/ Black.

Strange that they changed color codes after all those years....