Hey guys I have a s4 chassis with a s5 engine. I need to fix the wiring difference here:




I have the S4 harness that matches the 4 plugs in the picture. Can I take the plugs and wires from the s4 harness and add them to the s5 and use it that way or is there another way around this?

Any feedback is appreciated.

 

No one? I know people have done this before.

 

your using s5 engine harness? the s5 engine harness wont work on an s4 chassis. the plugs will be different

 

I know they're different, you can see that in the picture. But you can make it work. I have the s4 harness also.

Can I pull wires from the s4 harness and add them to the s5?

Or do I need to splice in the male connectors from my s4 harness to my s5?

Or can I possibly run my s4 harness and use a s4 alternator? (the fuse boxes seem to be a little different)

 

Use the s4 harness. Even if you use the connectors from the s4 harness and put them on the s5 it won't work because the ecu won't fit. Just use the s4 harness and accessories or convert your wiring over for the altenator and s5 accessories. There is a write up linked in the recent s4 to s5 intake thread.

 

Why wont the ecu fit? You must not understand what I'm talking about. This harness I'm talking about now doesn't even go to the ecu..... And my JDM harness and ECU fit just fine... No need to go with American harness and ecu.


I also own a s5 N/A and was wondering if I could maybe use the dash harness from that car and make it work? Or would I need the cluster from my s5 also? I have a boost gauge on my pillar so I don't need one in the cluster.

 

The series five EM harness will not connect to the series four FRONT harness in the passengers foot well.

The alternator wires on a series four non turbo do not have a path to the left side of the engine bay unlike a series four tURBO car who's alt wires do travel to the left side of the engine bay.

No idea whatsoever what type series four car you have and am guessing you have a series five turbo engine with series five turbo EM harness on it.

You do know what I mean when I say the EM harness of a series five will NOT connect to the series four FRONT harness in the passengers foot well?

There are two distinct harness in the left side of the engine bay. One if part of the FRONT harness and the other is the ENGINE harness (engine harness connects to the CAS, , battery posts, oil level sensor, start motor).

The CAS wiring in the series four cars is part of the ENGINE harenss and then connects to the FRONT harness on the left side of the engine..........whereas on a seies five car the CAS wiring is part of the EM harness and does not travel to the left side of the engine bay.

The ENGINE harness is not part of the harness on top of the engine (fuel injectors, afm and such minor items). The ENGINE harenss is just what is shown in the back of the series four wiring diagrams book that is online and free for a download..

So you apparently have a series five engine who's EM harness is now on the engine and is also connected to the ECU. Unfortunatley you ECU will never see any power 'cause your series four FRONT harenss will not connect to the ECU (FRONT harness supplies power to the ECU whether series four or series five).

One of those white plugs on the left of your engine bay supply CAS signal from the CAS to the FRONT harness and from the FRONT harness to the ECU......that is true on a series four car. On a series five the CAS signal is in the EM harness and goes directly to the ECU.

I'd ignore what you have posted and have a look to see how your going to get power to your ECU (series five). Ain't a comming from the series four FRONT harness cause it won't fit the seires five ECU unless you've already done a bunch of wire swapping over there in the passengers foot well. But if that were so you would not have made this thread 'cause you'd have known what your asking isn't?? reaonable.? and you'd have figured it out already.

Also the fuel injectors power comes from the FRONT harness which in turn connects to the EM harness on a series five car. The elect plug has a name and that name is X-11 (on series five cars) but this same X-11 will NOT connect to the series four FRONT harness....'cause the plugs are different sizes/shapes/number of wire b/t seire four and five cars.

 

Thank you, your answer is very helpful.