Hey guys Ive been imersed in my swap project for some time now. I've managed to get the engine and tranny installed with an aftermarket Holset H1C turbo. Now Im at the point of the wiring. Ive been researching it for a while, and still come up with more questions. I have found a few write ups that state I dont have to do anything with the original se wiring, just supply power to the new computer. But still Im curious how the gauges and stuff inside will still function propperly. Wont I need to splice something from the harness coming out of the drivers side into the TII harness? I mean those wires control the gauges and stuff in the dash right? So surely the need to go somewhere... My harness for the TII came complete but... at the end of the ecu harness are two plugs that go into the ecu, and then theres another bigger (more pins) plug thats about a foot before those two plugs, where does that go? I also have a plug that came attatched to the ecu and all it has is about 2 feet of wire and its cut off. After looking at the manuals I've discovered that harness is for the coils and stuff so that must be the left side harness everyone talks about. But what is that other plug, and how do I wire up the drivers side stuff? Im sure Im not the first one to put a s5 in a se, so surely someone can give me a step by step or direct me to one. Im kinda just getting sick of messing with it... Any help would be so greatly appreciated...

 

Correct you will need to connect the oil pressure, water temp, voltmeter, low oil warning light, reverse lights, and starter wires to the SE harness. The connectors are very similar to the S5 components, nothing too hard there.
As for the rest of it, that plug you refer to on the S5 engine harness goes to the FC's "Left side" harness, which is basically the FC's body harness. You will need to recreate the appropriate parts of this harness for everything to work correctly. The parts you need to get plugs for and wire up are the coils, fuel pump resistor/injector relay, main relay, circuit opening relay and main fuseblock (located on the FC's driver side strut tower)
I found it easiest to get the whole body harness out of a junk FC and to "strip it down" to what you need. If you need more detail let me know. I just did this about a year ago, so feel free to ask me for help.
Sean

 

Oh awesome... Think you can help me to Identify what those wires are? I've tried looking around in the manual at the schematics, but I just get lost... I can take some pics if you'd like...

 

Here are the plugs in question...

 

Oh one other thing I was wondering... Can I use any of the factory relay on the SE or do I have to cut them all off and change them over?

 

i have a harness already made to be put in the S.E,it powers up the coils,main relay,all you need is 1 ignition power,1 main 12v power,and ground,everything else plugs right in to the leading and trailing coils,plugs right on to the main relay ,main fuse block,circuit opening relay,and plugs into the stock e.c.u,then from there all you need is a s5 TII engine harness and you are good to go.if interested i will sell to you and make your life a little more easier.



i ran this harness on my car for a year with no problems,swapped it out for the s4 harness,because s5 needs the oil metering pump to be plugged in,in order for the car to run good,and since we all have to change out the front cover,the s5 metering pump can no longer be used,so i had mine plugged in and tucked away.

all i did was get a harness from the fc and stripped it down to what was needed.