MY10 XS with cold climate pack...

When the heated rear screen is switched on, either on it's own or via the demist programme switch, the radio goes very quiet and broken up.

The radio reverts to normal the moment the rear screen heater is deselected. The heated windscreen has no adverse effect at all.

Any thoughts please?

I could be wrong but I would say that's prob an earth problem Nomad

Thanks Steve T.

Probably need a trip to the dealer as anything beyond changing a bulb is pure witchcraft.

Radio behaves like that on mine too.
Probably all FM/AM head units do likewise.
Can't remember if the elements in the rear window act both as a heater and aerial. If so, that would explain why. Another member of the failed FL2 clutch/DMF club, twice.

Isn't the radio antenna in one or other of the side windows?

FM aerial is in one of the rear side windows and DAB aerial is on the opposite side.
(Sorry can't remember which is which at the moment)

If that's the case, the cause could be that the cables for the HRW power and head unit aerial run together somewhere and the increase in alternator ac ripple when switching on the HRW is producing noise. Another member of the failed FL2 clutch/DMF club, twice.