power source

[thump16]

okay square body guys. What wires are you using from the truck's firewall to power the ECU and LSX harness. Pics would be cool too. I know that the purple wire from original starter harness goes to ls starter but i want to make sure I am doing everything right. Thanks in advance

[ls1nova71]

Use the big heavy gauge red wire that originally went to your HEI to power the ignition relay for your engine harness.
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[clinebarger]

Red is battery power
Pink is ignition hot

[ls1nova71]

Originally Posted by clinebarger

Red is battery power
Pink is ignition hot

That's generally true, but did they change sometime between '73 and '87? Because I pulled an HEI out of I think a '79, and got the power wire for it and it's definitley red. Ok my phone sucks and it looks pink in this pic, but it's red.

[clinebarger]

Originally Posted by ls1nova71

That's generally true, but did they change sometime between '73 and '87? Because I pulled an HEI out of I think a '79, and got the power wire for it and it's definitley red. Ok my phone sucks and it looks pink in this pic, but it's red.

Im putting a LQ9 in a 77 C10, The HEI lead "was" pink kinda a dirty off white now. The B+ wires were A real light red. The colors on my 85 burb are still vibrant so Pink/Red are easy to spot. I generally go by the White terminal on the end of the HEI wire.

The wire you have looks red to me, Maybe someone replaced the wire on the 79. As far as I know all 75-86 large cap HEI power wires were pink. 73/74 still used points

[mooseknuckles]

Originally Posted by clinebarger

Im putting a LQ9 in a 77 C10, The HEI lead "was" pink kinda a dirty off white now. The B+ wires were A real light red. The colors on my 85 burb are still vibrant so Pink/Red are easy to spot. I generally go by the White terminal on the end of the HEI wire.

The wire you have looks red to me, Maybe someone replaced the wire on the 79. As far as I know all 75-86 large cap HEI power wires were pink. 73/74 still used points

mine has the pink wire that used to go to the HEI, this is a switched 12v constant right?

[Dustytrix]

Glad yall asked that question, I will be starting in a few weeks. Ok does this pink wire go to the stud on the ecm?

[mooseknuckles]

I doubt it.....mine will be connected to a brown wire from my psi harness....

[clinebarger]

Originally Posted by Dustytrix

Glad yall asked that question, I will be starting in a few weeks. Ok does this pink wire go to the stud on the ecm?

Please elaborate. There is not a stud on LS PCMs.

[Dustytrix]

Sorry I meant fuse box, I guess I read ecm to many times.