wiring diagram and pinouts help

hey guys i'm trying to hunt down a wiring diagram for an 03 4.8 pickup. also the pinout for it. this is the computer and harness I have to splice into my truck harness.

also I need to find out what I should wire my fans into, I would like to set it up so that they turn on and off with my computer. I have been told that it is possible to do especially if it is set up with efi live, and that is the software my tuner uses.

i'm going to add any more questions I have in this thread so I'm not cluttering up this board. so if your good with wiring please check in from time to time.

Ask a specific wiring question. There are dozens of schematic pages in GM Service Information for that truck.

I used a Haynes reair manual from oreilly's. Engine and chassis wiring are in the back. Also Lt1swap.com has some useful info and pinouts on converting a stock harness to a standalone.

this isn't going to be a stand alone, i'll be merging the 2 harnesses togather.

What's the question though.

Quote:

---

Originally Posted by Lsx10

this isn't going to be a stand alone, i'll be merging the 2 harnesses togather.

---

if you are going to splice your lsx harness into your existing truck harness you will need a wiring diagram for the year the harness came out of and one for your truck.
i will tell you to do it right it is a pain in the ass and if i had to do it all over again i would send both harnesses(the engine and truck) off and let someone else do it. i do not recall the names of who can do it but i am sure someone will post up. from what i can recall they charge in the neighborhood of about $400 or $450 and let me tell you that is a fair price for that job.

current performance does it, I just don't want to wait for 6-8 weeks to get it done. and I have alot of things I would rather spend $450 on.

my question is for the fans mostly.
I need to find out what I should wire my fans into, I would like to set it up so that they turn on and off with my computer. I have been told that it is possible to do especially if it is set up with efi live, and that is the software my tuner uses.

The 03+ truck ECM can be made to do it off temp. The car PCM already can.

yes with my truck allen sent me the harness and the computer retune. basically the tune in the computer uses a unused pin for the fans (fans turn on when temp hits 195) its just a matter of knowing which pin in the computer and connecting a wire there

now does anyone have the full 2003/2004 truck wiring diagram? or do you know if its the same as a 2500 express van? I didn't think it was but i have one that someone sent me.