This is probably a bloody obvious question (and if so, I apologize for wasting the time & bandwidth), but what circuits from the original thirdgen engine harness are retained? I'm getting closer to the point where I'll need to deal with the electrical, so I might as well start thinking about it now...

I know that there are variations in the harnesses for the "new" LS engines to be swapped in, & that trying to account for all of those differences would be (at best) impractical, but I'm thinking that there should be a good deal of commonality on the thirdgen side of the equation.

Again, if this is/should be blindingly obvious, my apologies, but it sure wouldn't be the FIRST time I've made myself look a little dumb...



Thanks guys.

 

If I get what you're asking, I think the only circuits from the thirdgen you need to worry with are the ignition switch from the key and the starter, everything else is battery and ground from the ls harness

 

You still need to power the chassis as well, the wire that goes to the starter battery cable terminal originally.

 

To put it really basic. You need the orange wires that go to the back of the starter, to power the chassis as was already said. You need the purple starter wire to run the starter. You need the big pink ignition only wire, to trigger the various relays for fuel pump and what not.

Since I used the 4th gen fuse blocks...all i did was give the fuse blocks that ignition only pink wire, and a battery hot. Then just the starter hook up, and that was it. Few grounds here and there.

I only have a few wires coming from my bulkhead connector that are original to the thirdgen. Everything else got clipped.

J.

 

OK, thanks guys, that at least gets me started. I guess that thinking about the bulkhead connector is what got me to wondering about it.

I am indeed using a different fuse box that I grabbed from a 2001-ish Olds in the junkyard. I can just run the engine circuits through that which will make the engine sub-system mostly self-contained. Roughly how many circuits are retained (or, alternatively, how many are deleted) with the bulkhead connector?

Thanks again guys.

 

From Aaron's swap site linked in the sticky:

http://www.team3rdgen.com/modules/3r...s/99wiring.jpg
http://www.team3rdgen.com/modules/3r...ther_packs.jpg
http://www.team3rdgen.com/modules/3r.../1989_c100.gif

 

OK, I've got it. I don't know why it didn't "click" before, but it makes a lot more sense now. Thanks all.

 

Aaron did an amazing job with that write-up. Thankfully, he lives really close to me and is probably going to help me wire my swap.

 

yea I thought the question was just about the thirdgen circuits that needed hooked up to the ls fuse box. lol

glad you got it under control Rumble

 

You still need to hook up that chassis power somehow. On the LS1, it doesn't go to the starter.

 

Hmmm, that's not a bad idea... Maybe I'll figure out a way to twist five7kid's arm into coming over here when I'm ready to tackle that...

 

This is a fantastic topic because I am down to the wiring! I have never seen an LS engine in its original vehicle and unfortunately I tore my thirdgen down about a year ago so I'm a little uncertain on a couple VERY basic items.

So, V8Rumble, if you thought your question was obvious...check this!

I don't know how to wire up the battery, starter, and alt! Does everything go the the starter? Or Alt to battery, or what combo?

I have a stand-alone LS wire harness and I was planning to use the original power feed from the old ECM. If I supply power to the C100 (as described earlier) will that provide power to that line? I will not be using any of the original guages.

I know this is your thread...but its the same topic so don't shoot me

 

If you had seen some of my electrical work, you wouldn't be saying that.

You know what they say, be careful what you wish for. . .