Alternator wiring and injectors and coils

[bh86]

Ok I'm swapping an 02 5.3 into my 82, I'm using a 91 suburban wiring harness and I've stripped the tbi stuff out. I'm curious if I can use the stock wires for coil, injectors, ECM 12v, ECM 12v with key, and whatever else. I'd like to avoid using an aftermarket fuse block as much as possible. Thanks for any help!

[truckdude239]

Im not understanding there is just no way the 91 harness will fit the 5.3 you can use it to feed power to the 5.3 harness. But theres nkt enough wires in the 91 harness for 8 injectors and 8 coilss

[bh86]

Yes I know that I am using it to feed the 5.3 harness is all.

[littlevictories]

if there's enough room for the 2 relays (3 or 4 with electric fans) i dont see why not.

[bh86]

if im using the factory fuel relay what else do i need for a relay? I'm a lil new at this so thanks for the help!

[ls1nova71]

The problem with what you're trying to do is the power from the fuse box (where the fuses you're wanting to use I assume are) is powered by the ignition switch. It won't handle the load of the LS harness. You need to run the LS harness off of an ignition relay to take the load off the switch. You could rewire the fuse box and have it powered up by the relay in the fuse locations you want to use, but it won't be easy. The fact you asked this question leads me to believe you've never done a swap like this before, so for a first time swapper, I think you'd be getting in over your head. Please don't take that the wrong way, as I don't know your skill level, just trying to help by keeping things simple.

[BR3W CITY]

Your trying the right ideas, just from the wrong harness. You can cut a stock LS harness DOWN to do what you want, but building the 91 harness UP just won't work out.

[truckdude239]

Need to let the ls harness control the fuel pump

[bh86]

I guess I worded it wrong. I'm only looking for the power supplies to come from the 91 harness. I think I found the correct info on lt1swap's Facebook page. I'm still not sure where to run the volt gauge tho

[ls1nova71]

You won't have to do anything for the volt gauge, its in the dash harness and reads voltage there. To power up the ignition relay, use the wire that originally went to the coil, it will stay hot during cranking, a lot of circuits in the fuse box will loose power while cranking. You will NEED a seperate fuse block for the engine harness though.