Bracket Boy

iTrader: (2)

So as I have read many rework their own harness for the engine or buy one from someone. I want to be able to run the LS engine and a 4L80E trans, in tank fuel system, fans, power windows, AC, electric speedo etc from the same harness. I have seen the one from Painless, but the price was less than painless!! LOL I am not sure if their harness eliminates all the stuff I wouldn't need to run an LS in an older car. I looked at American Autowire and a friend mentioned using the Isis stuff. Not sure what to do at this point. Has anyone used any of this stuff or have other options to throw in?
Thanks
J.

Pocket

iTrader: (22)

What car is this going into

Very few companies or individuals will offer a fully integrated harness because that requires an extensive working knowledge of both the donor vehicle and the car your swapping into

deuce4935

iTrader: (2)

If you have a stock harness then it can be reworked to control both the ls1 and the 4l80.
If you're looking to purchase a harness thats already setup, then contact www.psiconversion.com, they have prebuilt harnesses available and will build you a custom harness if need be.

Bracket Boy

iTrader: (2)

Oh sorry I thought I mentioned it is going into a 67 Chevy II.....

Mike52

iTrader: (1)

J, correct me if I'm wrong but it appears you're looking for a fully integrated harness that includes the engine, trans, PCM and the rest of the car's functions (you mentioned power windows, AC, fuel system, gauges, etc). You also mentioned the ISIS wiring system, it's a very good, very easy to install with less wires than a normal harness but also a very expensive system. It is more of a 'body' wiring system, it's not suited for the LSx/4L80E/PCM management so you can rule that one out.

If you're looking for an 'off the shelf' all-in-one wiring harness that includes everything to wire your Nova, I don't think you're going to find one for the reason Pocket mentioned. The closest you're going to get is a combination of a couple of harnesses (one for the engine-trans management and the other for the body of the Nova) from Painless, American Autowire, etc. If you don't want to or have the skills to build the harness yourself the other option you have is to take the car with everything installed to a wiring specialist and let him build you a complete harness, you would soon realize the cost of a Painless kit is a bargain.

JMO,
Mike

scatillac

iTrader: (12)

Yep. That's the way that GM does it in the late model stuff. The two harnesses talk at the fuse/relay box.

On '60s-'70s Novas or Camaros, it can be made quite sanitary, just eliminate the OEM alternator connections and pick up the body supply lead at the point the alternator battery lead is connected.

mcdonald77

iTrader: (21)

look at www.currentperformance.com, there prices are not to bad, but you get what you pay for!

deuce4935

iTrader: (2)

To the OP, is there any particular reason you're looking for an all in one type of harness? If the vehicles chassis harness isnt in bad shape then getting the engine harness wired in is pretty simple if you have patience to read and understand wiring diagrams.

Bracket Boy

iTrader: (2)

Thanks for the replies guys! I was thinking of doing a new original harness for the car and one for the engine and trans. I was just wanting to see if any had any other ideas that might be better without breaking the bank. A friend of mine is thinking of doing the ISIS system on his 66 Vette, but he doesn't have to deal with fuel injection etc.....
Thanks again.
J.

psiconversion

iTrader: (5)

ISIS appears to be a really nice idea, but as mentioned above, it is rather costly at this point. At PSI we like the idea of being able to keep the engine harness separate from the body harness. This modular approach lends itself to easy diagnosis of issues that may arise. For instance, if you are having problems with your headlights, etc., you dont have to go tearing into the engine harness to find the issue (I know injectors wont be on the same circuit at headlights, but I mean from the physical harness standpoint). Additionally, it keeps the cost manageable. If you want to use a painless body harness you can purchase that at one stage and later on purchase your engine harness. You dont have to shell out $1200 at one time. Just our philosophy for what its worth.

FastKat

iTrader: (10)

I don't know of any off the shelf products for what you are trying to do, but you can definitely make your own solution out of a PCM + harness and a fuse box + harness. For instance, my car has a 2006 Sierra 2500 HD 4L80E PCM harness and PCM, and a 2008 Impala fuse box and harness. I integrated the two together (for the circuits they share) and eliminated only what I didn't want. For instance, I didn't want any of the fuel tank sender stuff, but I did want functions from the fuse box, such as headlights, horn, windshield washer, fuel pump, electric fans, A/C compressor control, and other stuff. What's nice is that you can start with everything, and take out only what you don't want.

This did take a lot of time, but if you like wiring & electronics it can be a fun project. I probably had more fun doing this harness than any other part of the car... but I'm a little weird, too.

bjamick

iTrader: (31)

You want to keep the 2 harnesses separate from each other. You don't want one huge harness that controls everything. Have a harness and fuse box for engine controls, and a harness and fuse box for body controls. That's how the factory does it and how most swappers do it. Don't know if that's what you were asking for or not.

psiconversion

iTrader: (5)

Fastkat, Painless makes an integrated harness for some muscle car applications, but it isnt cheap!