I had a chat with a friend of mine about this - he's a research scientist who specialises in electronics, so I understood maybe one word in ten (although that could be his accent, he's from the Midlands).
His belief is that it's a fault in the charger that runs through the common earth with the radio, and that separating the earth circuit would be a good idea even if changing charger to one that isn't sub-standard.
My understanding is that the body of the car is the common earth, and I struggle to see where you'd find another/separate one, but then I don't make the electronics for experimental medical devices, so what do I know?
His belief is that it's a fault in the charger that runs through the common earth with the radio, and that separating the earth circuit would be a good idea even if changing charger to one that isn't sub-standard.
My understanding is that the body of the car is the common earth, and I struggle to see where you'd find another/separate one, but then I don't make the electronics for experimental medical devices, so what do I know?