Simply had to share this moment with you. I struggled a bit with this part to be honest, but I’m really pleased that it now works as intended.
The horn worked just fine earlier on (see the It’s alive! post), but after having moved the bike from the shed to the living room (yes, she’s lovely and understanding… And I now have to vacuum once a week without complaining), nothing seemed to work.
Checked all the wires, rechecked the wiring diagram, since I had been messing around with the wires from the head light, but no luck. Checked the connection between the ignition switch and the battery, and that seemed fine as well.
As a last desperate attempt (should have been my first), I removed the battery and hooked it up to the CTEK charger, even though it was fully charged approximately one month ago. Right away it began making a really loud ticking sound, and two of the LED’s were flashing rapidly. Thought that something was wrong, but after having read the manual it appears that this was the “desulphation phase”. Read more here: Smart Charger FAQ.
The next day the battery was fully charged and I was once again able to use the horn.
I then installed a turn signal flasher winker relay, and finally everything lit up like candles on a Christmas tree.
Lesson learned: These batteries apparently drain pretty fast.