Not sure if this is in the right section. If it needs to be moved please do so.

I have a 1998 A4 Formula. I want to swap out all the harnesses and everything else need to upgrade the car to a 99+. By doing so I have been told tuning the car becomes a little easier. Car has a 408 and decent sized cam. I also would like do a 4L80 conversion next. When I say I want to change out everything I mean the engine harness, fuse boxes(engine bay), harness under the dash, etc.

Here is what I believe I need to have to make this swap. Please correct me if I'm wrong.

99+ A4 engine harness
99+ interior harness
99+gauge cluster
99+fuel tank, pump and all

Some of the questions I have are as follows.
*I know I definitely need to use an A4 harness for the motor, but is the interior(under dash) harness different from an A4 to M6 car?
*Do the interior harness and fuses boxes have to be specifically from a Firebird or would a Camaro one work?

I know I can repin the connectors to the PCM for a 99 but I think I have issues with the fuse box and some of the stuff under the dash so I just want to swap it all out.

Any help is greatly appreciated.

Carlos

 

Hey Carlos you have some decisions to make early on with regard to what options / route you can go with a 98-99+up swap.

First decision sets the stage for all the rest. Which tuning software are you planning on employing? HPT or EFI Live?

Both are fine products but each has a little twist.

With EFI Live you can preserve your 98 cluster and sending unit by making changes to the Operating system that can be made at the tuner (or anybody with a copy of EFI Live) level.

If you are employing HPT you will need to swap the cluster- there are 35 wires on the 98; 99+up only uses 17+ you will have to splice in a serial data wire. You will also need to swap the sending unit in the tank.

If your state's emissions requires you to have the acutal VIN of the vehicle in the pcm you might have issues with HPT as it uses a VIN based licensing system. If your state doesn't care, then you could put a ficticious VIN that satisfy's HPT in the newer pcm.

The main engine harness is completely seperate from the body harness in the engine bay-power, fuses, and the interior body harness. If you swap the main engine harness for a newer (99+up) harness you will have to swap the interconnect plugs in the car on the passenger side foot kick panel. The 98 has 3 interconnects, the 99+up only has 2. You will have to look up the wires and parse down 3 connectors worth of wires down to the two. You will not have to cut or add or splice-just pull and fill in the remaining 2(there are enough empty spaces on the two 98 plugs to do this).

The main benefits to a swap like this with a N20 car like you have would be running EFI Live's Custom Operating System #5 that pulls timing and adds fuel all with the stock pcm all at the push of a switch without having to reload motor and N20 tunes.

One other note, if you plan on swapping the 98 instrument cluster bear in mind that the older cluster was in charge of sending the turn on signal to the alternator. If you run a "newer" main engine harness the pcm will take care of it with RED pin 15.

Doc

 

i just did this swap on my 98 ta. all i needed was a 99+ engine harness and a 99+ cluster

the only thing that has to be done is repin dash cluster connector and the 3rd connector in the passanger side i took me like 5hours.

the only problem is that the abs and air bag module are not conpatible with cluster but still remain functional.

 

Can someone walk me through what do I do with the wires under the dash on the right side please

 

Can someone walk me through this

 

I have a 98 camaro and a 99+ engine. 99 engine harness. 99 fuel tank. 99+ cluster. 99+ steering column. All matching key ignition pcm and bcm. How do I wire up the 2 plugs 99+ harness to the 3 plugs 98 harness