J-Rod

Here is a n00b question.

When doing a conversion I see folks chopping up some stock harnesses. I also see other folks using aftermarket harnesses. So, here are the questions.

1. Is there a restriction on which PCM/Year/Model you can use in a conversion (like say a 98 only) with the aftermarket harness?

2. Which harness do most folks seem to have the best luck with?

CamaroCain

iTrader: (1)

Painless wiring harnesses are setup for the 97-98 pcm only. But Speartech will make a harness for any year pcm.

I hear nothing but good things from people who use Speartech(sponsor)---->

Now for a question from me, what are you converting, J????

Stu Cool

iTrader: (13)

Check these GM parts out also posted by Oscar Will in another thread:
*************
Since I am a Chevy dealer employee (30 yrs) I am using everything right out of the GM Performance catalog for my 1935 Ford project. The parts really aren't that expensive when you start comparing. The GM Performance "Hot Rod/Street Rod" PCM for the LS-1 (a matching harness is also available) is a real bolt-in part. The programming is "spot on" and with a stock LS-1 there is no tuning required. My hot rod runs like a banshee, idles like a swiss watch and even gets great economy.

these are the GM part numbers I am using,

PCM P/N 12480112

Harness P/N 12480113

There is a little known but awesome "LS-1 Installation" book that is cheap and has LOTS of part numbers and conversion stuff in it that GM has put together P/N 88959384. It contains quite a bit of accessory drive info for different configurations, wiring diagrams, troubleshooting and diagnostics and even has some relatively unknown Holden parts in it that may be used in different applications. I recommend to anyone doing a conversion to check it out, even if you don't use all the GM parts it has great info......and it's from the guys that engineered these things in the beginning.

Check with your local dealer on pricing, some have really good deals for hot rodders.
************
Hope this helps

Pat

Jones'n

That GM harness also requires use of a 98 PCM I believe.

J-Rod

Thanks for the replies everyone, anyone else???

My goal is to sorta skip the older PCM if I can, as there tuning with them, and support sort of falls behind...

Lynda, I have a couple of cars that at some point need to be put back together. I could spend a ton on making a smokin' gen I SBC, or I could convert it and run a gen III and probably just as happy if not happier. I don't have anything firm yet though...

Also, a friend of mine is geting ready to do turn his 67 Camaro into a driver, and I think this would be a good idea for him.

J-Rod

GM PART # 12480112
CATEGORY: Emission Control System Hardware
PACK QTY: 1 CORE CHARGE: $0.00
GM LIST: $687.89
OUR PRICE: $481.53
DESCRIPTION: MODULE

GM PART # 12480113
CATEGORY: Engine Wiring Harness
PACK QTY: 1 CORE CHARGE: $0.00
GM LIST: $1,512.85
OUR PRICE: $1,058.99
DESCRIPTION: HARNESS


--------------------------------------------------------------------------------
GM PART # 88959384
CATEGORY: All
PACK QTY: 1 CORE CHARGE: $0.00
GM LIST: $49.95
OUR PRICE: $34.97
DESCRIPTION: LS1 ENGINE INSTALLATION GUIDE

matts22

iTrader: (2)

Get ahold of speartech, they seem to be the ones to talk to...at least that's what I've been told.

If you get a new pcm and harness from speartech, can it be used on any year engine tranny? For example, if I bought a '98 ls1/t56 combo out of a wrecked car, could I use a '02 pcm and compatible harness?

Oscar Will

That GM harness is designed for a 1998 type PCM, it was developed together as a "plug & play" setup.

Stu Cool

iTrader: (13)

JROD,

Where are those prices from? What Dealer or on-line source? I want to get the book to use while I am planning.

Thanks

Pat

Oscar Will

That book part number is from GMs' Performance Parts catalog, any GM dealer can order it.

Jones'n

1058.99 for a stand alone harness???!!! Now that is some pricey stuff.

Speartech

iTrader: (14)

That's just GM saying "People will buy it BECAUSE we're GM!"

79ls1

iTrader: (3)

I found a place on the internet that sales custom harnesses for any cpu for $800, and i have found a painless for $439 I ended up buying a stock 01 harness from American camaro and firebird for $195. The stock one didn’t really need much work to get it in running order just a little patience so I hope this info helped

Jones'n

You aint kiddin. I see that with a lot of stuff from GM, Just because they "authorize" it or something, it suddenly doubles in price. But people do pay, otherwise they wouldn't still be offering the stuff.

Gen3Benz

iTrader: (4)

Speartech all the way.
Their offboard programing harness kicks ***

badjuju342

iTrader: (3)

JRod,
Speartech will be 1/2 the price on the harness , or if you get a harness and have him convert it: 450.00 , Tennesse Auto can sell you a used harness , that GM price is insane!

81LS1Camaro

iTrader: (1)

What Gen3Benz said

John B

iTrader: (10)

GM sure got greedy on their pricing! I had Speartech redo my '99 F-body harness and it works like a champ. I believe that it really doesn't matter which harness you start with between the truck F-body or Y-body. Just be aware of the drive by wire for the TB application and matching PCM.

DaleMX

iTrader: (4)

Here ya go!

https://ls1tech.com/forums/lsx-parts-sale/264920-98-wiring-harnes-sale.html

under_construction

iTrader: (1)

Speartech will build you whatever you need for a very fair price. John did a great job on the custom harness for my C5 race car, and can set up for any PCM (I use an '02 A4 in mine) and accessories you need.


BPC5 from the corvetteforum