09 Express Harness?

[gmech68]

For the ease of the DIY swapper making their own stand alone harness for a ly6/4l80e combo, is the 07-09 express ly6/4l80e harness the easiest to do? I would think that you would just have add your relays, fuse block, 12v switched, 12v hot and a few more things.

[Blasphemy]

All I can say is.. diagrams, diagrams, diagrams. Most harnesses aren't created equal and yet can be equally complex. If you're planning on doing your own harness, just know that it's extremely time consuming and often frustrating. I learned a lot doing my own harness and there are things I would do differently the next time. www.lt1swap.com will be your harness bible throughout the process as it was mine, plus the owner of the site (Brendan) is really good about returning emails to questions you might have. And for the record, I don't think there is an easy harness lol

[gmech68]

I concur 100%. I have been doing just that for the last few weeks. I have relied on Brandon's site a lot for info and yes he is great with responding. I am where you were on your first harness, both learning and frustrated. But I guess that is probably one of the best ways to learn. I am close (I think) to having one complete. To be safe I will post a copy of my pinouts for critique and others to use. My thought with the express harness we're not having to change the trans wiring around on a non 4l80e harness.

[gmech68]

I have not been able to find a 07-09 ly6/4l80e express van wiring schematic/ diagram yet. So if anyone has one that they would like to share, it would be greatly appreciated.

[Tootall]

I have not been able to find a 07-09 ly6/4l80e express van wiring schematic/ diagram yet. So if anyone has one that they would like to share, it would be greatly appreciated.

google is your friend . . . you've gotta use it !

http://lt1swap.com/E38%20ECM%20Connector%20Pinouts.htm
http://ls1tech.com/forums/conversion...swap-faqs.html
https://forum.efilive.com/showthread...one-harness-s&

[Tootall]

http://cjnn.xtremefabricator.com/lsx...sSchematic.JPG

use these words for searching E38 PCM T42 TCM or LY6 harness

[gmech68]

Thanks for the great advice, I'll have to try that. How do you spell that again?

This is my first ls swap and I am 100% green with automotive electrical systems. I've got the pinouts that I needed, I just wanted wiring diagrams so I could understand the system better. The express van is the only vehicle that I know of that uses the ly6/4l80e combo.

How's your blazer coming along? Looked pretty sweet. I found it searching for info.