I have a question about the wire running from junction B to the battery for 7970 Di2.
Let me explain my situation:
My old bike (Addict SL) was running the full external wiring harness, with an internal seat post battery (bought from eBay seller 'eapathome'). To achieve this I cut the battery wire, and soldered red-red and black-black to the internal battery. The wire was run through the drain hole at the bottom and rear side of the seat tube, found on most Addict frames. This worked perfectly.
My newest bike (S-Works Venge) is now running the full internal wiring kit (EW-7975). I have cut the wire running from the battery holder to the internal connection (with the 6.5mm non-waterproof 4 pin connector) with the intention of soldering the plug (and run of wire still attached) to the wire from my internal battery.
Upon stripping this wire, I have found that it contains 2 red, and 2 black wires within it. This is different to the external harness battery wire which only contains 1 red and 1 black.
I need to know which pins require power from the battery and thus which wires should I connect my battery to.
The options are either to join my internal battery wire to either one, or both wires at the same time.
At this stage I'm not willing to touch wires and 'see how it goes' so I thought I'd see if anybody has has experience with this.
My next step is to buy a multimeter and try and determine which wires go where, both around the harness itself and to which pin at the internal battery connector.