Let's back up a bit...wiring harness basics?
 

I am still on the fence about whether to re-work my original harness or send it off to someone. I am a pretty good DIYer with an electricians background so circuits and wiring are nothing new to me. My question is this, for your regular run-of-the-mill LSx swap, what sensors or connectors are needed? Obviously, I know about the major ones, but some seam to be in a grey area and that is very confusing to a person in my situation. Another way of looking at it is, how many connectors should be on a re-worked harness. Maybe we can keep the answers in somewhat of a specific formula...

Connector/Sensor Name, Required/Suggested for best results, Needed for emission, Needed for auto tranny

I'll start with an obvious one...

Throttle position sensor, required, all, all tranny setups

Hopefully this makes some sense. I have been looking for this info all over the web and nobody has it listed this clearly. Please help me fill in these blanks. :waah:

Re: Let's back up a bit...wiring harness basics?
 

No one wants to play along??? I thought this would be fun and informative for the whole family. :lol:

Re: Let's back up a bit...wiring harness basics?
 

There's a lot of diagrams and info about this in the "How to swap LS series engines into almost anything" book. As for me I amgoing to send mine to John at www.speartech.com.

Re: Let's back up a bit...wiring harness basics?
 

I have that book and while I wouldn't call it worthless, it's not near as informative as I was hoping. Most of the info that I see is geared more towards the LS1s and other "car" engines. Obviously a lot of it is good for all the LS engines, but the detailed pin outs and charts etc by-and-large were not for the LSx series.

Re: Let's back up a bit...wiring harness basics?
 

everything you need to know can be found
HERE


Specifically this page

Re: Let's back up a bit...wiring harness basics?
 

Well, let me think. I'm going MAF-less, here's a list of everything I have (T56/LQ4)

IAT (trucks have maf/IAT in the same plug, so I had to separate mine)
Throttle body (DBW)
Front O2 sensors
Knock sensors
MAP sensor
Temp sensor
Injectors
Coils
Crank sensor
Cam sensor
Alternator
Oil pressure
VSS sensor

I think that's all I'm using.

Re: Let's back up a bit...wiring harness basics?
 

Thanks Thealien, I've run across that page before, I guess I just need to study it further. I realize the blue highlighted stuff is a requirement, and the yellow highlights are optional if you want full emissions but I am a little embarrassed to say, what about all the others? What about all the pins that ARE NOT highlighted in any way. This stuff makes me feel dumb from time to time. :help:

I guess I am to the point where I need to just pull out my harness and start dissecting it, been trying to to all the studying first before I dove in.

Thanks, that's what I was looking for!

Re: Let's back up a bit...wiring harness basics?
 

Just for refernce, this is what is left on my harness after W4M reworked it:

2006 Silverado harness, starting at PCM connectors and moving out from the PCM -

BARE WIRES:

White - To tach, 4cyl signal
Green/White - To fuel pump relay control, 12v +
White - To brake light switch, cruise
Purple - To brake switch, for TCC
Green/White - VSS, to speedo
Green - To OBD II connector, in vehicle
Brown/White - To SES light

3 Red wires - Each to a 12v key-on fused power source
1 Orange wire - To a 12v battery fused power source
1 Purple wire - To starter solenoid (tie trucks starter wire to this one, or leave it alone and use trucks wire to the starter)

CONNECTORS:

• Electric fans (high and low, I will have to supply the ground)
• TAC module
• Wires for cruise: Dark Blue, Gray/Black, Gray
• DS coil packs
• DS injectors
• Alternator
• Coolant temp sensor (front of left head, for PCM)
• Ground
• Starter solenoid (see “1 Purple wire” above)
• Crank sensor

MAIN HARNESS SPLITS IN TWO HERE:

One:

• MAP sensor
• Passenger side O2 sensor, front
• MAF
• PS coil packs
• Ground
• PS Injectors
• Throttle body

Two:

• Knock sensor harness on intake manifold
• Oil PSI switch (behind intake manifold, for PCM)
• Cam sensor
• Ground
• Driver side O2 sensor, front
• Transmission, drivers side
• Transmission, VSS, tailhousing
• Transmission, passenger side

Re: Let's back up a bit...wiring harness basics?
 

The sixth line down on that page

WIRES THAT ARE NOT HIGHLIGHTED REMAIN UN TOUCHED. THEY WILL GO DIRECTLY FROM PCM TO A PLUG, (SENSOR, SWITCH, DEVICE ETC.)

Re: Let's back up a bit...wiring harness basics?
 

Sorry, I'm blind!

Re: Let's back up a bit...wiring harness basics?
 

Critter, I am in the process of doing it now, and it makes a lot more sense once you start tearing into the harness and see the actual wires that they are talking about. I have three of the pages from the lt1swap page open and am referencing them all as I go along. It is really not as bad as you would think. I also come from an electricians background so I know what you are saying. It seemed much more daunting before I started. Of course I won't know if I did it right until I go to plug everyhting in and it either starts up or does nothing!!