It's easier and not all the wiring connections are done at the ECU. There's a bunch of wires you have to connect elsewhere going toward the SMJ and engine fusebox.Im considering a swap on my gc8, ive done swaps on other cars and I was just wondering why its necessary to cut and solder wires instead of repinning the connections at the ecu?
At this point you actually have to put on your thinking caps. This red wire is Sensor Power Supply WRX B135/9 – RS B136/15 ... This wire branches into three wires. One wire goes to the ecu, one to the RS engine bay, and the other to the bulkhead of the RS. The WRX has the same thing but you have to think about what you need. If it goes to the RS ecu then you can cut it. Same goes for the RS engine bay. What ever this powers on the RS engine wont exist once you have a WRX motor in there so cut it.
On the WRX side you have the same three branches but only one is cut. The one that know needs to lead to the RS bulkhead harness. Splice this in at the junction.
I have access to all factory diagrams and I print them out to write notes as I work on different connections. My swap "merge" is very atypical though...Question:
For people who have NOT done a merge yet, what part of the process do you find the most difficult/intimidating? Do you have access to factory wiring diagrams/pin outs?