Stand alone wiring harness

**kris** · 07-25-2012, 12:24 AM

Is a buying a stand alone wiring harness worth the money or is it easy to modify the stock harness?

The engine is a 2001 LS1 from a Camaro SS.

Will be swapped into a BMW.

***pajeff02*** · 07-25-2012, 03:11 AM

With the correct schematics, an understanding of engine electrical systems, and patience you can certainly modify a harness. That being said, you are probably further ahead with an LS specific harness that you then interface with your chassis. Do you have the stock Powertrain Control Module (PCM) from the donor car?

**kris** · 07-25-2012, 04:38 AM

Originally Posted by pajeff02

With the correct schematics, an understanding of engine electrical systems, and patience you can certainly modify a harness. That being said, you are probably further ahead with an LS specific harness that you then interface with your chassis. Do you have the stock Powertrain Control Module (PCM) from the donor car?

Yes, I have the stock PCM and I want to use it.

I have been looking at harnesses from Painless etc. , but if the modifications needed on the stock one are minor it would be a nice alternative to buying a new one.

***pajeff02*** · 07-25-2012, 04:53 AM

Biggest issue will be interfacing your gauges. What transmission will you be running?

**kris** · 07-25-2012, 05:05 AM

Originally Posted by pajeff02

Biggest issue will be interfacing your gauges. What transmission will you be running?

Stock T56.

***pajeff02*** · 07-25-2012, 05:22 PM

That certainly makes it easier as you won't have to worry about any interface issues. Any pics of the project?

**kris** · 07-25-2012, 10:59 PM

Originally Posted by pajeff02

That certainly makes it easier as you won't have to worry about any interface issues. Any pics of the project?

No pictures, as I am currently researching.

**the951racer** · 09-18-2012, 05:35 PM

I bought a LS1 stand alone harness book from F-Bodies Inc. on ebay for like 24$. I am currently in the process of doing an LS1 conversion into my Porsche. The book is pretty awesome. Has pinouts and all the modules and sensors laid out for you.

***Firebirdjones*** · 09-19-2012, 02:23 PM

Depends on the time you have on your hands

I've heard horror stories with electrical gremlins on some swaps, could have been shoddy workmanship though.

I've done handfull of retro swaps and just prefer now to buy a ready made stand alone harness. Figure there is less chance of a gremlin popping up, and I daily drive it so dependability is top priority.

I've used Howell for the last 3 swaps and I've been extremely happy. It's just like a factory harness, same color coded wires (so diagnostic later down the road can be done with factory manual) and all weather packs, wrappings, looms, just like OEM. (Some of the other vendors are not). Also comes with relays and fuses as needed.

What was nice also was that I used LS1 style dual electric fans which wasn't part of my 6.0 truck harness anyway. Sent Howell a picture of the weather pack connector for the fans and they made the harness with it. Everything labeled so it was just plug and play. Just tell them what vehicle it's going in and where you want to mount the computer. The harness is then made the correct lengths. Has always fit perfectly.

With electronic throttle body, they also made wires for cruise control as an added bonus, all I needed was a switch to run it. Everything labeled so it's simple plug-n-play. Definately worth the price to me.

**the951racer** · 09-19-2012, 07:24 PM

Hhhmmmm. Even I may have to check into that. Sounds pretty nice

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***Firebirdjones*** · 09-19-2012, 07:36 PM

It's nice, but it's a little pricey too just like anything else worth having it seems. I thought they were in the realm of competative though when I checked around.

I can't put a link up, but if you google Howell Engine Management it comes up. They are up in Michigan.

**the951racer** · 09-21-2012, 02:29 AM

Cool sounds good. So they make me a complete new harness for my existing PCM or they provide a new PCM as well. I do have a full harness and PCM with the motor. If I decide to go tis roué guess I could sell to recoup some of the expense.

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***Firebirdjones*** · 09-21-2012, 07:08 AM

Originally Posted by the951racer

Cool sounds good. So they make me a complete new harness for my existing PCM or they provide a new PCM as well. I do have a full harness and PCM with the motor. If I decide to go tis roué guess I could sell to recoup some of the expense.

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Yeah the harness is all new stuff. You can do a GM computer from them or keep your own, that's up to you. They will tune the computer before shipment however if you go that route, so all unnecessary codes are eliminated, VATS, and other things so it's turn key and go. Their kit only had 2 or 3 wires to hook up which is typical of any retro swap you do.

One was for the fuel pump, and there was key on power, and a wire that takes power all the time. After running those where they needed to be, the rest was plug and play, mount your computer, fuse panel and relays where you want and you're done.

**the951racer** · 09-21-2012, 05:53 PM

That is sounding better and better even at the high cost

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***Firebirdjones*** · 09-21-2012, 06:40 PM

I don't mean to shy you away from doing it yourself. It's not horrible to do with the schematics and pin outs in front of you and a little patients. I'm just too picky for my own good.

**the951racer** · 09-22-2012, 02:24 AM

Yea I had ya. I may end up doing it on my own still. One of my best buds was in the custom audio business for a long time so it's no problem for him to re-wire an entire car. I think I'll be recruiting him with some beer and pizza.

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