Need Electrical Help

I am confused about the wiring of the starter, voltage regulator, and alternator on my 68 V6 225 odd fire. I have searched this forum and the internet, but can't understand what I have found. I need a wiring diagram showing the connections between these parts.

I have a Motorcraft alternator, Delco starter, and a "Mighty" voltage regulator. The regulator has terminals marked I,A,S, and F. The alternator has terminals marked as shown in picture. I have 3 wires ( purple, red, green ) coming thru the firewall bulkhead just above the heater box and the drivers side.

I also have a HEI distributor. I do not have the OEM wiring harness that is connected to a OEM voltage regulator.

A sketch of the battery, HEI, voltage regulator, alternator and alternator and the wires connecting them would be great. Wire size would be a plus.

I'm not just looking for a quick answer and then run. I feel I have researched as best as I could especially with my limited knowledge DC. I'm sure there are others out there that will appreciate the information.

Thanks

 

This should be what you need. On your purple red and green I need to know where they go under the dash.

 

Thanks, will check tomorrow.

 

WALT,
The purple wire goes to "st" terminal on ignition switch. Red goes to "Batt" terminal on ignition switch. Green goes to "ign" terminal on ignition switch.

ANOTHER ISSUE:
I checked the switch while I had it out behind dash.

In "off" position acc and Batt posts have power on them ?????
In the first click position Batt post has power.
In the second click position Ign, Acc, Batt post have power.

Seems like I need A new switch.

Yes it did but not totally, voltage regulator tags different than mine.

 

The purple will go down to the "S" terminal on the starter solenoid.
The Red wire will go to the BAT terminal on the back of the alternator.
The green will go to that Bat/ign terminal of the HEI.
Note1.. On the "R" terminal on the starter solenoid, install a 12 ga wire and connect it to the green wire at the HEI.
Note2.. Connect the RED (+) battery cable to the big stud on the starter solenoid along with a 10 ga wire that connects to the "BAT" terminal
at the alternator.
Note3.. Recheck the back of the ignition switch labeling. Sometimes it can be misleading. You may need to move the wires to the opposite side of the label..

 

Walt, I basically got it wired as you say today after thinking about it last night and looking at old notes. Got it to crank, but did not run the 12 ga wire to hei as u say. Will finalize tomorrow. Than you so much for the clear, simple directions. I'll make diagram.

I think the ignition switch is shot. some times it would test ok, sometimes not. also notice one of the posts would turn when I tried to tightened. Thank you again!!!!

 

Just one little idea. I think one of the best electrical upgrades out there for these jeeps is an internally regulated Delco (10si, 12si) alternator. Three simple wires, more output and easy to wire up. You definitely have to consider the correct wire size for the higher output. Just an idea/suggestion.

 

Yes u are correct, eventually, a total wiring upgrade. Need to research buying a harness or building one myself. Thank you

 

Yes the switch is no good and not repairable.

 

Walter,
What is the function of the additional12 gage wire going to the HEI?? Is this wire spliced together at the connector of the green wire already going to HEI?

Quickie valve cover question. Does the small sheet metal cover that bolts to the valve train go under the oil fill hole in the valve covers? What is its function? Thank you.

 

That piece of metal under the valve cover is a baffle that is positioned under the oil fill. It is there to help deflect oil from being thrown off the rockers from making its way to the oil fill and causing a potential leak.
-Donny

 

It is known as the ignition by-pass. When the ignition switch is in the start position, there is no power on the ign terminal. When the starter solenoid is in the cranking mode there is power applied to the "R" terminal of the starter solenoid. This power is temporarily applied to the HEI to start the engine during cranking mode only. This wire can be joined anywhere with the ign green wire.

 

Ok, I fully understand. I like understanding the function of the wires rather than just knowing where to connect them. Thank you AGAIN for your help

 

Thought so. Thank you for confirming.

 

Walter, Here is my final wiring diagram. Thank you.

 

Looks good to me Tomellen. Will answer your PM also.