I was just looking through some LS1 swap harnesses and seems the biggest difficulty in using the GM LS1 harness in a swap is the wiring issue. Then of course, there is the speedometer issue as well as the mounting problems, exhaust fitment, gauges and fuel. To cut down on these problems, I was thinking I might use an entire chassis harness from a LS1 car, along with the tank and fuel lines, and bolt it all in to the thirdgen. Do this with a 4thgen dash and I think I'd be all set. This will cut down on the fuel issues, gages, and take care of the body harness too. That and you can get that cute little remote that LS1 cars have with ABS if you wanted it bad enough to swap front brakes. What do you guys think?

 

sure...if your wallet ressembels a bottomless pit filled with $100's.

 

I still can't understand why people think that the wiring is a big issue, 8-10 wires and it's running with no problems.

 

Depends on if you are doing the wiring yourself, or paying someone else to do it. There are a few cars I've seen that swapped the entire dash and all the wiring from a 4th gen donor car into their third gen swap. It's a lot of work though - best if you can do it yourself.

The tank and fuel lines are easy enough to do - I've got 4th gen tank and lines in my car.

 

If you go through all the trouble to swap an LS1, you better be willing to do some head/cam work and serious tuning. An LS1 has a LOT of potential, but if your going to do all that for 320hp and 330 ft-lbs then there are much easier and cheaper ways to do it.

 

If you really want a 4th gen dash, do it. If not, it's not worth the trouble. If you start it, you really can't go back. Be prepared to finish it or sell the car at a loss.

Even with using the body harness, there are a lot of things that are not compatible or have to be converted. If you think getting an LS1 harness to work with a stock dash is hard, do not even attempt to use the 4th gen body harness. I probably have 40 or so more splices swapping connectors then you would just interfacing with the stock dash.

But heh, it is cool to have factory alarm, keyless entry, auto headlights, retained power, and a nice fuse/relay panel under the hood.

Kevin D.

 

I think your missing the point as to why people do LS1 swaps.


As for the wiring, if you do your research, get the wiring diagrams for your car and your motor, you can splice all the wiring in just a couple of days.

 

Now the keyless isn't hard at all to splice in. I know a guy who did it, and I'm going to do it with the GTA as well. May even go a step further and splice in the 98+ body control module to get the dimming interior lights, the and the alarm system as well.

 

Of course none of it's really that hard to add in to anything. Hell, Dakota Digital has several like modules for retrofit applications.

We are talking about a guy that wants to swap an entire body harness in to 'cut down on problems' though.

Kevin D.

 

Splicing wires I'm not concerned about. I have a spare Z28 dash at the house, and a thirdgen, and a chassis harness, and 2 crate LS1's. It'll take me just as much splicing to make the gages work with the LS1 if I just used the body harness. Oh and yes I've done it. My '94 came to me as a bare shell, and I had to transplant it's complete harness, drivetrain and everything into that car after I totaled it. So it shouldn't be that big of a deal... did it all under 2 weeks.

I plan on building my my 6.0 soon after the retrofit is done. It's going over 400 cubes with some TEA stage 3 heads, cam, and intake, as well as exhaust.

 

I dont see how you could possibly think swapping the entire body harness into a thirdgen would be easier than the 8-12 wires it takes to wire in the LS1 ECM to the 3rd gen body harness.

But, its your project, do what you want

 

What you are failing to see is that on your 94, the ends fell into place. That's not going to happen on a third-gen. You'll have to change:

front and rear light wiring
devices in the doors
column wiring is different
HVAC wires are in the wrong places and different
Cruise wiring position is different
Wiper control is completely incompatible
Mirror lighting
You will have to swap door panels too or your lock/window switch wiring needs to be moved
Washer pump wiring is in the wrong place
Power antenna wiring in the wrong place
etc...

I guess I misunderstood your first post. I thought you wanted to make it easier. Like Steven said, using the 4th gen body harness will help you not worry about the 10-15 wires for the gauges and fuel pump, but you then added 40-50 wires to change and or splice.

I guess, after re-reading, to answer your post; yes the idea has been done before, its no where near as easy or easier, a good bit of people are using the 4th gen plastic tank WITHOUT the body harness, and the fuel lines from the 4gth gen are not going to work (the bends at the front frame rails are too different).

Kevin D.

 

That's the thing. I'm using a 4thgen dash, column, door panels, etc...everything in the car except the body itself pretty much is 4thgen. I know I'll have to extend some wires here and there, but for the most part it's just like relocating the parts from one chassis to another except they're slightly different. Am I still missing something?

 

The window motors are different, door locks wire up differently, wiper motor is totally incompatable, cruse control hooks up different. HVAC controls from what I hear is a nightmare to make work on a 3rd gen, taillight harness, hatch release, and power for the pulldown, headlight harness is different you would have to splice in all the plugs from the 3rd gen harness, it's more of a pain than just keeping the 3rd gen wiring and splicing the wires to get power to the motor.

 

I had exactly the same thoughts and ive put in the dash.. hvac.. and the complete body harness that i spliced into the TA wiring. I now have like 8 splice points instead of the one that I would of had having the ecm tie into the stock

If you want the look of the 4th gen interior.. go for it.. i thought it would be easier, fawk was I wrong.