I'm swapping an s4 tii into my s5 n/a chassis using a haltech 1500 terminated harness. My question is on the body harness (one coming out of drivers side firewall) if thats what it would be called, what can i get rid of ? do i need the fuel pump resistor relay (haltech controls fuel pump?). and the little pressure sensor that bolts to the passenger strut tower? im sure ill have more questions, i just started putting it back together but i want my engine bay to look decent.

 

I’ll just start with a short comment and say the crank angle sensor wiring exists on the chassis wiring coming down from the driver side engine/chassis harness.

basically I’m saying the stock ecu has 3 connectors. 2 for the engine harness. 1 for the chassis which has the wiring for the crank angle sensor.

id assume fuel pump signal exists in this same connector.


Edit: I’m thinking of the opposite side of the firewall from you, so you should probably disregard my comment.

 

I’d rewire the fuel pump wiring though. Use the haltech for fuel pump signal to a relay. I’d get rid of the old fuel pump wiring and run new wires, you’d be surprised itll up fuel pump voltage and give you more headroom on afr’s.

 

I have a rewire kit which I planned on using to bring a higher gauge to the pump. The haltech has a plug for cas if remember correctly. Im most likely not going to need that fuel resistor. And I believe since I have to upgrade to bar map sensor I can get rid of the stock n/a sensor. You have rhd I’m assuming ?

 

I was talking about the passenger cabin side of the firewall when you were talking about engine side.

And yes you will use your map sensor with the haltech and get rid of the n/a one.