Anyone know much about ST225’s my reverse light is playing up. Bulb and bulb holder good. Earth to bulb holder good. I have 11.5 volts at the bulb holder tested with my power probe. But that voltage is not good enough to light a bulb. I’m guessing the switch it good because if you put it in reverse with the wipers on the rear wiper switches on. If you leave the car in reverse the light will flicker and sometimes light up after a period of time. Anyone know how it’s wired?