[hatzie]

Originally Posted by Gregski

Wired up my LS starter (it's an iddy bitty thang) last night and got the engine to turn over by turning the key in the ignition switch. I like taking baby steps and not taking on everything at once, so I will share what I did to make this happen, I know this is super easy, but here it goes if for nothing else to hear myself say it, but it may help someone out:

(battery stays in the OEM location on the passenger side)

1) Main thick black battery cable goes from the negative battery terminal to the front of the passenger side cylinder head. (hole in OEM battery cable terminal had to be enlarged slightly to accommodate the metric head bolt)

[just for completion in addition a skinny black wire runs from the battery negative terminal to the radiator core support, to ground the chassis - that's unchanged]

2) Main thick red battery cable goes from the positive battery terminal to the thick stud on the new LS starter.

[that's nice, but nothing happens at this point, yet]

3) In keeping with tradition, we run a medium thick red wire (yes that is a technical gauge description in my book, ha ha) from that same thick stud on the starter in #2 above to the bulk head black little square box on your firewall by the brake booster. This supplies main power to the cockpit.

[at this point if we was to turn the key, our gauge cluster should light up, but that's about it... oh and our annoying always on fan will start to blow... Joy!]

4) at this point power goes from the battery to the starter (logically that is not necessarily how the electrons flow, but don't tell my Biology teacher, hee hee) and then daisy chains from the starter to the bulk head, and more specifically to the ignition switch on the steering column (no not where you insert the key... but below) ok but still no clicky click on the starter, unitl ... [wait for it] ... until we run the purple wire from the bulk head black little box on the firewall by the brake booster back to the starter's skinny winnie stud. This purple wire is the "signal" wire it tell the solenoid (aka electronic switch) on the starter when to turn ON the starter.

... and that's it folk's aside from the battery cables, it's just a two wire hookup, the red and the purple wires. I know I made this silly but I hope it helps out the OverThinkers(TM)

I blew up my bulk head / fuse block to show you that the red and purple wires are just pass through and do not feed the fuse block directly, I actually like to divorce them from that box and run em through a different hole in the firewall and not the bulkhead.

For a high current connection like the 12ga Red Circuit 2 wire I'd bite the bullet and extract the old terminal so I could crimp on a new Delphi terminal to insert in the bulkhead plug. It's a PITA to pull the male Packard terminals out of a connector but this connection is a wee bit more than slightly critical. Butt splices tend to heat up and get loose over time. Brass Delphi terminals, crimped with the proper tool, do not.

GM didn't put a lot of circuits in the 1973/74 bulkhead plug. The 79 & later trucks had a lot more realestate in that plug along with ATC/ATO fuses rather than glass cartriges... It does take a little body work to fit the larger bulkhead plug tho.