Engine harness
On The Tree
Joined: Feb 2009
Posts: 130
Likes: 0
From: san antonio tx
thats a hard to answer man,, since it all depends in your budget or willingest to read/trace wires to do your own, modify the original into a stand alone myself just as a lot of guys do it... but there is also lots of guys that buy them... just my .02
Thread Starter
TECH Enthusiast
Joined: Jul 2007
Posts: 670
Likes: 1
Very true, i'll probably sit on the floor cutting and splicing for a couple days...
If you're going to do it yourself, first make sure you have a good set of schematics. If you need them, sign up for AllDataDIY. It will cost about $25 to sign up and register one car for a year. You can download all of the engine schematics then. If you need to get some for the car the motor is going into, it will cost about $15 more for the second car. If the harness is a 99-02 f-body all the schematics are posted in this section already.
On The Tree
Joined: Feb 2009
Posts: 130
Likes: 0
From: san antonio tx
dont now if you have but if you havent you can try www.lt1swap.com there is tons of info and maybe it could help you understand more... but my opinion re doing my harness wasnt that hard,, but I have done alarms and remote starts on cars b4 check the link above. what car is this going into? what engine/pcm year do you have?
Trending Topics
will be making my own. between lt1swap and pocket's postings on thirdgen, I think I've got the info I need to roll my own. I've got more time than money for wiring and the harness was included with the motor.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Currently reworking my 2006 L59 harness.
Almost done and not as hard as I thought it would be. I am using the information from LT1swap.com and have no previous wiring experience.
Almost done and not as hard as I thought it would be. I am using the information from LT1swap.com and have no previous wiring experience.
I mod stock harnesses for use. Most arent even LSx to begin with
Expect 20 hours to 3 days for a beginner to rebuild one
Most LSx schematics are posted all over the web. Finding those is not hard. Finding your swap car's is the trick. Common ones like old GM trucks, 3rd gen Fbodys, Fox ponys etc are well covered too so you may get by without
Necessity is the mother of invention. Its why I started
Thats common on all GM stuff. Different engineers draw the diagrams every time and a common nomenclature isnt established. Usually this requires tracing each individual wire through a multitude of schematics to see exactly where it goes, what it does and if its required. I ran into that issue with 3rd gens for a long time when 2/3 of the body connectors are simply labeled "Fueling and injection systems". You're really going to flip when you see a schematic be wrong 
. Thankfully this is rare
Its just a big game of connect the dots
Very true, i'll probably sit on the floor cutting and splicing for a couple days...
If you're going to do it yourself, first make sure you have a good set of schematics. If you need them, sign up for AllDataDIY. It will cost about $25 to sign up and register one car for a year. You can download all of the engine schematics then. If you need to get some for the car the motor is going into, it will cost about $15 more for the second car. If the harness is a 99-02 f-body all the schematics are posted in this section already.
I've got more time than money for wiring
the most confusing part is matching the LS1 side to the LT1 side. The diagrams give very different names for the same wire.
. Thankfully this is rare
Almost done and not as hard as I thought it would be. I am using the information from LT1swap.com and have no previous wiring experience.
Thread Starter
TECH Enthusiast
Joined: Jul 2007
Posts: 670
Likes: 1
dont now if you have but if you havent you can try www.lt1swap.com there is tons of info and maybe it could help you understand more... but my opinion re doing my harness wasnt that hard,, but I have done alarms and remote starts on cars b4 check the link above. what car is this going into? what engine/pcm year do you have?
I've done a little bit of wiring myself.
I'm not sure what I'm going to get yet, I am looking for a complete truck take-out 6.0l. And it is going to go into an early A-body Pontiac.
Last edited by StrokerTA; Feb 9, 2010 at 08:24 AM.
I used a truck engine and harness. Was very easy to do once I fiqured out what was needed. Bought a complete set of service manuals for the engine. You can search this site also and find just about every wiring diagram you will need.
I would not pay someone else to do a harness if you have a little wiring experience. It is that easy to do.
I would not pay someone else to do a harness if you have a little wiring experience. It is that easy to do.
Did my own..I have a pretty good thread detailed on wiring for LS Engines..
https://ls1tech.com/forums/conversio...o-lt1-car.html
https://ls1tech.com/forums/conversio...o-lt1-car.html
Ya I'm having a hard time finding anything on my 93 4cyl coupe. Trying to figure out which wires on the body harness need 12 volts so all the lights and stuff works.
I did my own harness using the 5.3 fuse box and wiring harness.
I did my own harness using the 5.3 fuse box and wiring harness.
I did a four cyl coupe a while back and left everything on the chassis harness in place. Literally remove all that is connected to the enigine and in engine bay except for the wires for headlights and airbag sensors on the front end/engine bay. Eveyrhting else can be pulled and is more or less stand alone/doesn't need to communicate at all with the new engine/ecu harness. With exception to the starter solenoid wire of course.
I did a four cyl coupe a while back and left everything on the chassis harness in place. Literally remove all that is connected to the enigine and in engine bay except for the wires for headlights and airbag sensors on the front end/engine bay. Eveyrhting else can be pulled and is more or less stand alone/doesn't need to communicate at all with the new engine/ecu harness. With exception to the starter solenoid wire of course.
That is what I found to be simplest. Then I just jumped the solenoid on the starter from the main hot to the starter motor. Ghetto I know but it made for a cleaner install.... Using the solenoid you just run the big power supply cable to the starter and then at the starter install a small 14-16ga wire from the supply cable to the solenoid. Its backwards I know but is so simple and requires nothing on the chassis side. That or you can run your hot from the battery to the starter and then run a wire from the ignition switch down to the starter solenoid on the starter. I just didnt like where the wire had to run/lay....
Plus the mustang solenoid provides a good place for alt charging wire etc.
Plus the mustang solenoid provides a good place for alt charging wire etc.
