I am working out the w123 300td cluster led upgrade. Current issue I've run into (and not had chance to mess with fully) is the seatbelt warning light only goes dim rather than going off as it does with an incandescent bulb. Is this another bulb such as the alternator bulb (which I have worked up proper solution for, to be tested and written up in the next week or two) that does magical things other than simply indicate?