Rear DeFog and Radio Static

[Cisc0]

So I've been chasing this FM static and last night while it was raining cats and dogs in NYC I'm listening to the radio and no static. Once I turn on my rear defog the radio stations go crazy and it is full of static. I turn it off and crystal clear reception.

Does any know of the correlation between these two components?

[PropellerHead]

Originally Posted by Cisc0

So I've been chasing this FM static and last night while it was raining cats and dogs in NYC I'm listening to the radio and no static. Once I turn on my rear defog the radio stations go crazy and it is full of static. I turn it off and crystal clear reception.

Does any know of the correlation between these two components?

On the E39, the rear defrost grid acts as the FM and AM antenna (and analog TV if so fitted). It would not surprise me if the E53 is the same.

[Quicksilver]

There shouldn't be a correlation between these two components. But you never know.
I just found out that the side window drivers side has the radio antenna so they are close by.
Let us know what you find out. I have no static but I could get better reception.

[PropellerHead]

Originally Posted by Quicksilver

I just found out that the side window drivers side has the radio antenna so they are close by.

THAT'S what that is! Man, I have wondered ab that for YEARS! You know what else I wonder- is it reversed in RHD X5's? Any Britons care to chime in?

[X5Sport]

Nope. Aerial installed on the nearside (left) of RHD vehicles. You may have either a poor connection causing arcing on the rear demister circuit, or if any part of it is used as an antenna then DC is getting where it shouldn't. There should be a DC choke to ensure that only AC radio signals get to the receiver(s) and not the supply volts which are DC of course. It's usually some form of capacitor, or capacitive circuit.

One other thought is a bad track on the demister may be causing an issue. Any sign of 'hot spots', which show up as uneven demisting? Could be a source of 'noise' in poor signal areas.

[jst2878]

2001 x5 over here. Same thing, rear defog=radio static. That's always going to happen