Hey guys. I have a B&M IQ Cyo headlight and a B&M D-Toplight XS taillight both powered by a Shimano DH-3D71 dynamo hub. When I plug the taillight into the Cyo the Cyo dims significantly. As soon as I unplug the taillight it is fine. I've traced all of the wires to make sure nothing is shorting and double checked all of the connections.
The setup didn't do this initially; only for the past few months. I emailed B&M through their website but have not received a response (contacted them a week ago)