Powering under dash fuse panel

[skyhigh4by]

most of the war through my LS swap trying to figure out how to feed power back in to the block under the dash. which original wires do I need to feed power back inside truck. There are 2 heavy gauge red (from buss & fron starter) also what about the brown one that was originally from alternator?

 

[diesel4me]

Would help if I knew the year & model of your truck..but..

"most" GM's from '73-87 used one or two thick red wires at the starter solenoid that went on the main stud behind the positive battery cable,those wire(s) go behind the bellhousing and over to the firewall to a junction block,next to the brake booster--.there are fusible links in those wire(s) near the solenoid,and at the junction block--from there they feed into the fuse box..there is also a thick red wire that tees into those wires,that one goes to the stud on the back of the alternator..
The brown wire on the altenator is probably the field excitation wire that sends 12V to the field terminal on the two wire plug that should only be hot with the key in "run" position..the other small red wire on the plug stays hot all the time..

 

[skyhigh4by]

Sorry it's an 82.

 

[skyhigh4by]

Mine has 1 large wire from battery-starter, 1 red from starter-buss(on firewall), 1 red from starter-alt(charge wire?), 1 red from starter-thru firewall connector, 1 red buss-thru firewall connector, 1 red buss-alt, 1 brown alt-thru firewall connector.

Batt->starter(red)

Starter<-alt(red)
->buss(red)
->firewall(red)

Buss->firewall(red)
->alt(red)

Alt<-firewall(brown)

My new harness has all the alternator wiring in it already as well as starter solenoid. New harness connects to battery power and also has IGN power wire that I've connected to the wire that used to power up the coil.

If that's comprehendable. Which of these wires can I eliminate and which need battery power for the fuse panel under the dash?

 

[blazer74]

I ran a larger wire from the starter to the firewall junction, I actually added an additional junction on the firewall for accessories. Ran a wire from there inside to the extra fuse panel.