Despite my best efforts, the old twin Hella horns were dead!
I took my car to my mechanic (not the same dungu) who trouble shooted the wiring and battery. In the end, it was found that the horn itself had malfunctioned. Out goes twin Hella horns, in comes twin Bosch horns (cost RM85).
It is loud but not as loud as my old Hella horns. The chap at the workshop did not have a Hella model and I did not want to waste time waiting for him to order a new one. So, for now, Bosch horns will do.
At least I have something to blast the incoming motorcyclists…