I added a GPS power connection in behind the WRR's headlight, using the Brown/Blue and Black wires from the unused connectors. The GPS power works (when the key is on), but now the gauges don't display anything, there is no backlight, no numbers and no status lights. The bike starts and runs. Horn, tail light and rear blinkers all work. Front blinkers don't work but the turn signal indicator light on the dash does light when the rear turn signals are on.
I've checked all the fuses, I've replaced the 10A signalling fuse with the provided spare, same result.