Volvo Repair: Noise from speaker after engine wash??, noise suppressor, koala bear

Question
Hi,

I got my 1996 850R wash today and the engine bay as well. After the wash I
noticed there is noise from my speaker varies by the engine's rpm. When I
turn on the radio or CD there was a terribly loud squeezing noise from
speaker as well. I disconnected the radio and the noise was better. but when
the brake light turn on and off as I step on the brake pedal, I heard to click
noise from front left speaker as well. Also, when I start the engine, the
squeezing noise can be heard more noticeably. Is there anything to do with
noise suppressor and any ground connections or else?

Thank you.

Answer
 Well Paul, By squeezing noise, I'm going to assume you meant "squealing noise"? Eh mate? If it varies with engine speed, you probably have a blown diode in your alternator. "Thanks wash guys" I would make them correct it as it did not do it before the wash. The only other possibility is a bad or disconnected radio ground. I assume it's even worse on AM band?
  Is squeezing noise the noise a Koala bear makes when you choke it? (:  VBG

Mark