I got a dual extruder v3 and I tried to connect the rightmost connector I realised it won’t fit. I don’t know what to do. The cable coming from the RAMBO has 2 pins and the connector from the extruder (right side) has a pin where it looks like it should be open (to receive the pin from the cable from the RAMBO) - it’s the third spot from the right on the back row.
The dual extruder V3 needs two connectors. Did you add the cable for the second extruder that came with it? (Hopefully, you didn’t replace the original with the one in the box).
As you are looking at the front of the TAZ, the cable with two pins should be on the left and the original cable with no pins should be on the right. Both connectors on the tool head have pins but the empty spots are different so you can’t plug them into the wrong spot. When you attach the tool head to the printer, I don’t think its possible to cross connect the cables as they aren’t long enough.
The instructions seemed pretty clear to me when I installed mine.
I had a v2 on my taz 5 and the leftmost connector fits perfectly. I did not add any new cables.
Re-read section 12B of the V3 toolhead installation guide were it talks about pins that may need to be removed.