Good question! I don’t know the reason why a semiconductor packed circuit board was used on these pre BCU cars. I appear to have gotten away with just switches wires and regular relays, time will tell...There are two heavy duty diodes in my concoction but that’s an unnecessary luxury simply because I couldn’t find a double gang toggle for the hazards with a led to match the others. The pcb even has a pic micro that appears to be there to drive the indicators, a £4 Landy flasher seems to work fine too. The only reason I can speculate why it might possibly have been used was to reduce the car’s initial build time, thus keeping production costs down?
