# Di2 wiring help



## TricrossRich (Mar 26, 2014)

Hey guys... I'm trying to pre-plan some Di2 wiring for a Shiv TT build and I was hoping that some guys with Di2 experience might be able to help me as I have no prior Di2 experience.

Here's the wiring scheme i've come up with.










I bought a very lightly used 6870 Di2 TT set up. Based on the picture, it appears that it comes with a shifters, FD and RD that I've labeled in the photo above. It looks like it also has a 5-way junction box and a JC-41 internal junction box. My plan was to hide the 5-way junction box internal just inside the head tube, along with one of the new BT/Ant + D-Fly boxes. I was going to drill a small hole in the tope of the seat post and mount a 3-way junction box under the saddle so that I could re-charge. Will this work? Thanks in advance guys.


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## rtalain (Dec 29, 2009)

According to this thread, you can use another JC-41 instead of the EW-90-B that you have planned in your downtube. It worked fine for this guy. He also put his junction box under his seat.

Di2 "A Junction" alternate location - Weight Weenies


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## Migen21 (Oct 28, 2014)

How do you plan to charge the system and connect to USB for etube software access?

Sent from my Pixel using Tapatalk


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## rtalain (Dec 29, 2009)

He would just plug into the Junction Box under his seat.


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## TricrossRich (Mar 26, 2014)

Migen21 said:


> How do you plan to charge the system and connect to USB for etube software access?
> 
> Sent from my Pixel using Tapatalk





rtalain said:


> He would just plug into the Junction Box under his seat.



Correct... In the wiring diagram above, the junction box is under the seat, so its easy access for charging. The problem with that wiring set up is that the system won't allow you to run two A junctions. I've found that some people do drop the A-junction in the frame and then buy a second A junction, pop the rear derailleur plug out, plug the wire into the junction and then plug the RD into the junction and you can charge the system.

This is the setup I ended up using...


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## rtalain (Dec 29, 2009)

VERY clean setup, and sweet ride!


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## TricrossRich (Mar 26, 2014)

rtalain said:


> VERY clean setup, and sweet ride!


Thank you.


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