Starter Wiring Issues

[Jay Don]

I have a 73 C10 with a 350. When i bought it, the starter was gone and the wires were cut at the starter. There were 5 WIRES running to the starter, plus that positive battery cable. I can't figure out how to get this thing wired back where it will start. The wires are so old i can't tell colors on the wires, but here is what i am thinking:

1--positive battery cable to the big post on the battery
2--red wire (i think) from the wiring harness to the big post on the battery
3--Purple wire (i think) goes to "R" or "S"?????

I know the purple wire is from the switch because it lights a test light when the key is in the "start" position. One of the other wires is yellow (i think) and it is hot when the key is in the "on" position.

Please help!!!!!! I don't care if i have left over wires--i just want the starter to engage.

 

[Ricko1966]

1 wire from ignition switch to solenoid to engage the starter. 1 wire from r to ignition coil to give more voltage at crank. Remaining wires go to positive starter post. Check continuity on the wires from coil positive to the starter wires the one with zero resistance goes to r the purple goes to s. Just reread your post your yellow wire goes to r.

 

[75gmck25]

The '73 is wired a little differently than later trucks because it has points (not HEI) and it has an ammeter in the dash.

1. large gauge wire/cable running to the battery positive. original factory was 2 gauge black, but many have been changed to red.

These first two smaller wires are also on the large starter post, and run up through a metal exhaust heat shield bolted to the back of the engine.
2. 10 gauge red power wire with 14 gauge fusible link running up and over to the fuse box
3. 20 gauge orange with 16 gauge fusible link running up to one side of ammeter shunt. This wire should run up the firewall, and then above the engine there will be a bullet fuse housing and a very small fuse (2 amp?). This is the 12 volt, full power side of the ammeter shunt.

4. on the solenoid "S" terminal - 12 gauge purple wire from starter solenoid running up to the ignition switch

5. on the starter "R" terminal - 20 gauge yellow, 9 volt wire running to the distributor. Points get a full 12 volts when cranking, but only about 9 volts after the truck is running. This wire provides the points with 9 volts in run position.

1,2,3 are all connected together. 4 and 5 are on the other starter terminals. If you have upgraded to HEI the yellow wire is no longer needed. Most in-dash ammeters don't work anymore, so the orange wire is usually not critical.

 

[CalSgt]

EDIT: @75gmck25 beat me to it

My truck never had the wire to the coil like @Ricko1966 mentions, Dad tells me that’s a pre HEI thing.

1 heavy gauge from big lug on solenoid to battery

1 Purple 10 ga from ign. Switch to “S”

2 10 ga red wires to harness & alternator hook to the lug for the battery cable. NOTE: if the harness was cut off these two wires should have fusible links on them where they hook to the Solenoid.

1 yellow to “R” on the solenoid UNLESS it’s been swapped to HEI distributor then abandon it.