I have a high pitched whistle in the AM (693 in Melb Western Suburbs) section of the standard radio in my BA XT Falcon, that is ignition generated, I think.
It varies with vehicle location and it does not vary with engine revs.
Any help, please.

Probarbly just poor reception as the B and F series arent the best on reception strength as the antenna is incorporated into the windscreen if i recall. Is the FM signal ok and in stereo?

Rear window demister to be exact but yeah, and f**k it's a clean looking idea, I've been curious about quality of reception though.

Thanks for the responses people, but i think i have tracked it down. apparently new rear window tint is metalized and i was told by installer that AM reception can be iffy with metal tint, but "as nobody listens to AM radio we don't worry about it". can be replaced with non-metalized tint, slightly different colour for material cost - $50. Thanks all.-jerry500