Folks-
OK, here's a weird one for you. It's in a BMW 732i, but don't let that
fool you; this could happen to anyone.
I just put the OEM AM/FM/LW/SW/Cassette radio back in my car, having
had it out for a couple of years trying (unsuccessfully) to find
someone who could rebuild the cassette drive.
The radio "pops" when I put on the brakes. Just one "pop" when I hit
the pedal; other than that it works fine. The loudness of the pop is
semi-independent of the radio volume setting (i.e. you can hear the pop
if the volume is all the way down) but varies in strength according to
how long it's been since the last time I used the brakes. The longer
between brake applications the louder the pop. If I hit the brakes twice
within, say, 2 or 3 seconds, the second application produces no pop at all.
The pop is timed precisely with the illumination of the brake lights,
so I would guess the brake light switch is (somehow) the culprit,
but ...
(1) Why didn't it do this with the radio I just took out?
(2) How come the pop is stronger if I wait longer between brake
applications?
(3) Why doesn't something else react to this?
and ...
(a) How can I fix it?
I assume a capacitor, of the proper value and in the proper place, will
fix it, but I don't know enough electronics to know what size to put
where.
The car has no other significant defects, and no other wiring/electrical
problems/"fixes"/modifications.
Any suggestions?
-Shel
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