Differences Between 93-97 A4 Wiring

[greenz28]

I am looking to find a roller to swap my motor and trans into, preferably with a wiring harness already in the car. My car is a 94 A4 LT1 and I'm looking to swap motor, trans and pcm. I'm looking for an easy swap where the wiring harness from the new car will work with my stuff. Which years should I be looking at for the easiest swap?

Thanks in advance!

[Cathead]

The 1995 model will probably be the closest

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[greenz28]

That's what I thought. I wonder what will need to be done for the 96-97 to work?

[Cathead]

You would need to use the 96-97 pcm for starters. The shbox.com website will be very valuable to you.

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[SSlowBoat]

you can swap your motor/trans/pcm into any lt1 fbody except 93. the only significant difference is the coil plug (from dual to single) and the fact that a 96-97 has a crank sensor you will not use.

i swapped my 94 camaro motor/pcm/trans/rear/rear brake line DIRECTLY into a 96 firebird no issue. the trans wiring on the 95-97 has an extra wire, the pcm simply doesnt use this wire for a 94. you do not have to remove it, its just there.

just keep your pcm/trans combination correct (meaning 94 pcm for 94 trans, etc) and you will be fine

[SSlowBoat]

the bigger issue comes if you need emissions inspection. THEN you would have to use a 96-97 pcm.

[Injuneer]

The engine harness pinouts to engine components are basically the same, 94-97. The 96/97 harness just has extra connectors for the CKP sensor, EVAP purge vacuum solenoid, after-cat O2 sensors, and serial data.

Just means you will have pins at the PCM you can disconnect. If you have an auto trans, 94 trans harness has one extra wire for the PWM lockup solenoid. Shoebox has the PCM pinouts list for 95, marked to show where the 96/97 additions are. Note that the length of the 94 Opti harness connector is different than 95-97, so the short Opti harness can be changed as required.

95 pinouts w/ 96/97 marked in red:

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_pinouts


Where you get in trouble is matching the different year engine harness to the body harness. Shoebox also has the pinouts for each year of the body harness connectors:

http://shbox.com/1/harness_connector_faces.htm

You also have to make sure the wiring at the DLC is correct:

http://shbox.com/1/DLC_wiring.jpg

[greenz28]

you can swap your motor/trans/pcm into any lt1 fbody except 93. the only significant difference is the coil plug (from dual to single) and the fact that a 96-97 has a crank sensor you will not use.

i swapped my 94 camaro motor/pcm/trans/rear/rear brake line DIRECTLY into a 96 firebird no issue. the trans wiring on the 95-97 has an extra wire, the pcm simply doesnt use this wire for a 94. you do not have to remove it, its just there.

just keep your pcm/trans combination correct (meaning 94 pcm for 94 trans, etc) and you will be fine

That's exactly what I was looking for. I've been looking for a 94-95, so this will open up more options.

I'm in SC, so emissions inspection is not an issue. Thanks for the info!

[greenz28]

The engine harness pinouts to engine components are basically the same, 94-97. The 96/97 harness just has extra connectors for the CKP sensor, EVAP purge vacuum solenoid, after-cat O2 sensors, and serial data.

Just means you will have pins at the PCM you can disconnect. If you have an auto trans, 94 trans harness has one extra wire for the PWM lockup solenoid. Shoebox has the PCM pinouts list for 95, marked to show where the 96/97 additions are. Note that the length of the 94 Opti harness connector is different than 95-97, so the short Opti harness can be changed as required.

95 pinouts w/ 96/97 marked in red:

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_pinouts


Where you get in trouble is matching the different year engine harness to the body harness. Shoebox also has the pinouts for each year of the body harness connectors:

http://shbox.com/1/harness_connector_faces.htm

You also have to make sure the wiring at the DLC is correct:

http://shbox.com/1/DLC_wiring.jpg

I switched to a vented opti, so am I correct to think this won't be a problem?

My plan was to find a car 94-97 and use the existing harness in the car and just swap motor, trans and pcm. Does that make a difference?

[Injuneer]

The 95-97 vented Opti uses a longer connector than 94. A lot of the newer Optis have deleted the need for a separate "short" Opti harness and the unit comes with a new harness permanently attached, connecting to the gray connector on the passenger side of the intake manifold. If there's ever a question, you can buy the correct short Opti harness from places like EFIConnection.

This is another great Shoebox "clickable" photo:

http://shbox.com/1/harness.htm

[greenz28]

Perfect! Thanks again!