Where does the negative battery cable wire go?

[71CHEVYSHORTBED402]

Originally Posted by mr48chev

Your secondary ground wire off the battery cable just goes to a spot on the body where you are comfortable with putting it. It serves as a more direct ground to the battery for the lights and for other accessories.

The purple wire has to go to the S post of which ever solenoid you are going to use to energize the starter. Without it properly connected the solenoid isn't going to function and you won't be able to crank the engine.

You don't need the resistor bypass wire from the R post on the solenoid with HEI.

When I changed my 71 to HEI I ran the wire for the hei from one of the hot when the key is on pins on the Fuse block so I could run a heavier gauge wire to the hei.

Make sure that you have the correct HEI wire terminal to plug into the HEI rather than just use a female slide. A female slide will slide at an inopportune time if it loosens up just a tad. Been there done that.

My former mechanic wired the HEI the same as you, My new engine harness was built for HEI, but the harness contains the wire for the R terminal (points dist.) as a standard provision. It includes the TCS and anti-dieseling connects as well.

I called the vendor's contact to clear my head. He says you should connect it to "R" regardless, for what was no more than an explanation you could otherwise have problems. I'm guessing they're simply reducing their own exposure to unforeseen problems. I installed a mini starter that of course doesn't have an "R" terminal, so just cut the connector off, shrink wrapped the wire's end and tucked it into the harness.

[71CHEVYSHORTBED402]

For what worth seems I've finally wrapped my head around the junction block. The wires are in the "forward lamps harness", includes alternator. Works like this, corrections and that welcome.

The junction block serves to operate the battery gauge, and the connection powers the vehicle as well. The block’s stud terminal takes three wire terminals using a 3/8” hex serrated flange nut with #10-24 threads. The three wires are described as:

• One 12 AWG red wire with a fusible link. Reference “Red, 12 AWG with fuses” for further description.
• One 18 AWG black wire with a 4 AMP inline fuse, for the battery side of the battery gauge.
• One 12 AWG red wire from the positive battery terminal.
______________________________________________________

Black & White, 18 AWG: The circuit runs from #1 on the instrument panel connector to the fuse box. The wire has a 4 AMP inline fuse near the LH headlight. This wire is for the alternator side of the battery gauge.
_____________________________________________________________________
Red, 12 AWG with fuses:

The red wire’s 14 AWG fusible link is near the LH headlight before it’s soldered with the black and white wire mentioned above and three additional red wires for factory alternators.
• One red wire connects to the alternator.
• One red wire connects to the junction block with a 14 AWG fusible link.
• One red wire connects to the voltage regulator.

___________________________________________
The black wire with an in-line fuse is for the battery side of the battery gauge. The circuit's wire is black and brown inside the cab.

The black & white wire (alternator side battery gauge) and black & brown wire (battery side battery gauge) run to the gauge cluster.

______________________________________________
Big props to Vette's write-ups on the subject, it just took a while to finally click. He explains it's necessary to separate the two currents for the battery gauge. It's easy to see why the wires connected to the junction block, battery and alternator have inline fuse and links before they run into the cab.