There is a thing in the radio industry called a antenna null. That's when
you located between the original signal and a very strong reflected
signal.
It can knock out one or both channels and most times messes up the main
radio signal. I would try other locations it the city our out on the
highway
for a true test. As you know it's always best to use a strong FM station.
I had a '94 Corolla that lost it's FM. I was worried as I wanted to sell
the
car with everything working. The FM was so weak it has to be the antenna.
Not easy at all but I replaced it the FM was some better but not like it
was
months earlier. I also noticed the lamp in the radio occasionally would
go
dim then brighten again. I got to checking voltages to the radio. I
decided
to rotate the fuse with another of the same value. Say, how about that,
the
FM nearly blew me out of the car. I saw the owner a few years later and
ask
about the car and the radio. It's nearing 200,000 and said it all works
just fine.
