DIY DI2

[skimons]

Yes it works correctly. I also unplugged the FD when measuring, so I was able to understand the communication between junction box, FD and RD.

same here (RD works without FD), but i used all "original" parts.
any problems to expect when i tie in a battery on the front wiring harnass?

[manninen]

this is where the magic happened

4 wires to RD, including those soldered battery cables

4 wires thru original connector to gear switches, 3 on use

all done like in page 1 schematics

doing it wrong?

[manninen]

is it possible to press up/down shift buttons accidently same time on original Di2 system? at least they are very close together

just thinking i´ve burned front box by pressing both button at same time

it does sound good, but might be possible to press those buttons same time even on original TT switches

depends how they connect

[manninen]

could someone measure voltage on original fully charged battery.

my chinese is 7.64v

[Oilman]

Should be 8.4 when no load is applied. But at 7.6V the derailleurs should operate fine.

[Jeffr]

You can press the buttons at the same time. Electrically it is not a problem.

I can't see the colors and wires well enough to tell if you have a connectivity problem. Up shift and down shift go on the same RD wire. Should be green, I think. White should go to the fd shifter. Blue goes to both.

[manninen]

thanks, just thinking what i have done wrong. when you press both buttons at same time its kind of shortcircuit.
red, black and green connected together. but i guess shimano made it that way it doesnt matter

ok, 7.6v isn´t overvoltage

can someone test which indicates battery conditon. FD and RD plug off and press that switch to indicate
if green light doesn´t lit, plug RD and press again

cause i´m not getting any green or red here

search continues

[Jeffr]

why would red black and green be connected together if you're pressing both buttons?

Are you using a normal shimano shifter? If not it sounds like you have your buttons wired wrong.

[manninen]

if theres three wires they´re all connected when pressing them together, one "positive" 2 "negatives"

[Jeffr]

Are you using your own buttons or di2 levers?

[Jeffr]

I see, I looked one page back, sorry. Your own. You may simply have them connected improperly. There is one voltage source and three different button wires. You simply connect voltage to any button wire momentarily to trigger it. It doesn't matter if more than one button is connected simultaneously. They're all inputs except for voltage.

[manninen]

this is how it´s connected

correct me if i´m wrong


connected like pritchet74´s shimagnolos

[manninen]

ok, it works!!

somehow i blowed my front cable set/or it didn´t work as new (my best quess is static electricity)
just bought a new one and installed it

-battery condition information comes from FD
-you can press both up/down switches at the same time with out breaking anything

now i have to think about cranks, low Q or high stiffness (old dura-ace or sram rival, i have them both)

[Mike K.]

Success! Congrats! Great to see that your determination paid off!!!

[manninen]

quite a journey
when i started i didn´t know much what i´m getting into but skimons and jeffr helped a lot!
without jeffr i would propably fried that RD

this was right forum to get it thru