Originally Posted by jayvar

Ok so I was wiring up the fuse block and relays and I hooked up the Orange wires and noticed that the other side was not hooked up to anything and the diagram said it returns switch power to the pcm so I want to know where these hooks up.

Originally Posted by rodgebone

did numerous searches but cant find answers to these tough questions:

base info: '04 Holden LS1 swapped into a Jeep Wrangler using the LS1 computer exclusively but no PIM or BCM (deleted those from the wiring as i have aftermarket gauges and thought there was no use for them). i've yet to wire in the MIL but did wire in the DLC. ive been able to connect my laptop software via the DLC and observe engine functions without issue but cannot pull codes (even when i deliberately unplug things like injectors, sensors, etc...)

my questions are: is the reason i cant pull codes because i need the PIM (&/or the BCM) to convert the class 2 serial data signal from the PCM to a UART serial data signal at the DLC (would be pin 9 on the DLC and pin 6 for "diag enable" from the PIM)? why am i able to connect my laptop to the DLC and watch engine management or is that separate info from DTC signals (looks like the same wire providing both information from the PCM)? and does it have anything to do with the fact the MIL circuit itself is not present? do i need the PIM (&/or BCM) to run the MIL or can i simply run 12V to a bulb and ground it thru the PCM's serial data output? im worried there are differences in circuit voltages if i do this and dont want to fry the PCM. at present, the DLC is wired as follows: pin 2 is the PCM class 2 serial data output signal. pins 4 & 5 are grounds and are wired together (is this okay? ive seen differing opinions). pin 16 is direct 12 volt battery power. any help is appreciated. would like to pull codes (im sure there are many) before we go to the dyno shop for software editing. i seriously doubt i simply have no codes stored but spoze its a possibility (like winning Lotto). LOL. thanks in advance.

Originally Posted by Chevyrob

This may be a dumb question but I'm doing a ls swap using a 5.3 lm7 into a 87 Camaro I'm getting the donor motor and trans harness computer fuse block everything from the same vehicle if I eliminate the stuff listed in the forum that I don't need will I be able to use without getting the pcm flashed ?? I understsnd that eventually I should but just to get it going I'm on a tight budget. Thanks in advance

Originally Posted by G-Body

I cleaned this post up a bit and the wiring info is now in the attachments. The truck wiring is from my 2001 4x4 tahoe 5.3L, but be aware that the truck wiring seems inconsistent. I saw alldata diagrams for a 2001 4x4 yukon 5.3L and a few of the wires were different, even in the PCM connections


Heres a link to directions to build a VATS bypass box, remember this won`t work for truck,vette or GTO computers, they use a serial data signal which cannot be replicated. In these cars the VATS must be deleted in the computer.
http://temp.corvetteforum.net/c3/70lt1/vats.shtml
VATS bypass thread
Another VATS bypass design

Hooking up A/C controls

Dual speed fan connections

More fan connection info/diagram

Alternator hookup without using the PCM

Truck wiring with a LSx Truck fusebox

Differences between the truck and f-body wiring harnesses

98 AND 99+ retrofit wiring diagrams

Link to GTO pinouts

4L60E VS 4L80E wiring differences

A wiring guide courtesy of Rodder
http://www.blown.net/ls1swap/rodders...1t56wiring.doc

Using a 200R4 or 700R4 transmission and don`t know how to hook up the TV cable? Click here https://ls1tech.com/forums/generation-iii-external-engine/791429-tv-cable-throttle-cable-bracket.html

Power Steering pump output: https://ls1tech.com/forums/conversio...truck-etc.html

Molded Heater hoses! https://ls1tech.com/forums/conversio...ter-hoses.html