V3 dual head extruder wiring problem on Taz 5

I recently purchased a V3 dual extruder for my early model TAZ 5 with a 0.35mm nozzle.

When I went to install the head I noticed that the original wire harness with 4 separate connectors would not fit the V3 E2 wire harness.

I called support and the person I spoke to recommended getting an updated wire harness (V2C). The new harness arrived and it appears the pinout does not match the E2 pinout.

I’ve tried searching the internet for the wiring diagram to see if I need to rearrange the pins with no success.

I’ve attached a photo of the mismatched harness connectors.

It seems like the six wires on the left are correct, but I’m not sure about the other five (six on the supply side) and I’m not confident the wires of the new harness are correct at the main connection.

Can anyone help me with this?

Well the pins you’re wondering about are for 3 pins the Taz 5 does not have/use. One of which is just a guide pin, the two purple wires are the X-Max limit switch I believe.

No! the pins are fine - no need to change them.
Extruder pin-out drawing.


Just make sure the internal fan wires for the secondary extruder fans in the control box are there.

Thanks kmanley57 -

I got the similar input (without the wire diagram) from the Lulzbot Tech Support people and was able to complete the demo print.

But I didn’t get the advice to check the second extruder fan wires in the control box and I didn’t notice fan 2 running…

In the menu I see an option to control Fan speed 1 but not Fan speed 2. And when I turn up Fan speed 1, only Fan 1 runs as I would expect.

From the diagram you provided, it shows pin 7 and 8 as the extruder fan - these wires are not connected at the extruder harness connection point for E2. It appears that the fan wires for E2 run across the extruders to the connector for E1.

It also appears that there is a 1 for 1 wire for every connection in the control box. Any suggestions for how to control the fan for E2?

Thanks again.


I think both cold end fans are run from just one of the extruder connectors. I have not wanted a new dual extruder so I can not help you with any details and would recommend AO support or others that have one for that.