70_ss

Hey guys,

I am ready to send in my LS1 engine harness to get re-worked to a stand alone harness. This is going into a 1970 Chevelle. I just wanted to get some recommendations on who to send it into. I'd like it to be somewhere that will include the OBD2 port and a check engine light. Thanks in advance.

68BBChevelle

iTrader: (12)

Look into a www.psiconversion.com harness they look to be very nice and have a grommet for the fire wall to locate your harness under the dash for much cleaner look and weather friendly. Talk to Jon on here he is a sponsor.

99VetteFRC

I did mine myself.... wasn't hard at all. Took about 5 or 6 hours altogether... I downloaded schematics and used a junkyard DLC connector, 2 aftermarket relays and 6 circuit fuse panel from Auto Zone. I have less than $20 in my harness and when I put it in my '70 Chevelle it will hook to the starter, distributor power wire, and 2 battery cables. Very, very easy to do.

bullitt44321

I didn't modify mine because factory harnesses are so bulky.

I ordered my harness from STREET AND PERFORMANCE they do an awesome job

kSStamp09

iTrader: (4)

Currentperformance did mine for my '82 C10. they did a great job an were very helpful.

V8Rumble

iTrader: (9)

I've heard good things about both Speartech & PSI Conversions. I'm probably going to be doing mine myself, but if I decide not to for some reason, those two would be at the top of my shortlist, just based on all of the feedback I've read.

99VetteFRC

If anyone needs help I would be willing to give some tips. I also have access to Alldata at work, Could get some schematics and can try to scan them. I just need to find drivers for my ancient scanner.

Build-it-Break-it

iTrader: (9)

Same here^^^^ save your money and do it yourself. Put the money into other parts. Its easy to do and you can get super detailed and use braided loom.

LS1 pwrd NOVA

iTrader: (2)

Pm ing you

LS1MCSS

iTrader: (18)

If you need the 99-02 f-body schematics, they are here,,,
https://ls1tech.com/forums/conversio...chematics.html

CutLS

iTrader: (6)

99VetteFRC, Did you eliminate the emissions and the wiring for them? Did you remove the pins from the PCM connectors?
I've thought about just buying a new harness since it would have all the proper fuses and a fuse panel set up and just try and sell the stock harness. I think I may try to figure out what I need and don't need and cut my own. What is the best cost efficient harness wrap/sleeve out there?

99VetteFRC

I cut all the optins not being used out of the harness. Have not removed the pins from the PCM connector yet. I will do that prior to installing the engine. I have everything hooked to an engine stand at work and can run the engine on the stand. I moved the harness so all the wires come off the engine at the back center of the intake and am going to mount the PCM, fuse box, relays and DLC connector under the dash. I shortened several of the wiresso everything was the same lenth. I reused all the split conduit I took off the origional harness. I will post some picks or maybe a video later.

Project Builder

I have to agree. You can save some big coin by reworking your harness yourself. There is tons of info right here on this site and lots of people with first hand experience to help. Not only that but if you have problems after you install you will have all the knowledge needed to track down the issue and fix.

LS1 pwrd NOVA

iTrader: (2)

Yeah forget buying a harness. If ur doing ur own swap why not do the wiring also? That's what I am going to do. I think for us first timers doing our own harness, we are afraid but from all the people that did their own harness, it seems easy. We just got to take our time and double/tripple check it all. I think a good solid day working on a harness for our first time is all we will need.

99VetteFRC

This is the first conversion harness I've done, I am a certified technician and had plenty of experiance reading schematics and repairing OE harnesses. I would recommend studying the schematics very well before starting. It is pretty easy though. All the pink wires are fused switched 12v, all the orange wires are fused battery 12v, and black/white tracer is ground. other than that removing unwanted items are all thats left.

Rick Speed

iTrader: (55)

^ pretty much to the point only correction I would make or restate is the pink wires are run/start. Switched could be confusing for some people

99VetteFRC

Yes you are right.... run/ignition is the correct statement.

ricky levins

Do any of ya'll have the schematics for the truck harness? Or could someone send me in the right direction of working this harness. Also I guess I'd need an obd2 and a fuse box?

welldonecj7

iTrader: (13)

Lt1swap.com seems to have a lot of good info and wiring diagrams. I am still in the research phase so I can rework my harness.

itsslow98

iTrader: (18)

+10000 for PSI

Sell your stock harness and buy one from Jon. Hands down the easiest part of my entire swap was installing the harness. You can get like $200 for a stock harness.