Okay, one for the "experts"..
300 TDi disco, 1995 M. no ABS.we get a road-speed related crackle on the radio, sounds just like badly-suppressed ignition on a petrol engine does, except that it's not linked to engine speed, but road speed. Quite high frequency compared to the road-wheel rotation speed - about the sort of speed that I'd expect an ABS sensor to produce, say. It's definitely distinct pulses like a spark would produce, not a whine like an alternator
on the plus side, looked at the window ecu, and found exactly the same dry joint as was on that website. Wonder how many there are like that?