Re: Engine Feed Back in Radio

[ccrobins <ccrobins@ktc.com>]

Hi Dennis,

  Disconnect the radio/cd from the amp.  Start the engine and see if the
rear speakers still hum.  If not, then the problem could be in a
mismatch between the radio output and the amp input.  For instance one
could be single ended (audio ground the same as power ground) and the
other end balanced (audio ground isolated from power ground).  The
output of an audio transformer is usually not conncted to the power
(battery) ground, fer instance.  See if your amp's manual discusses this
in the installation section.  

  CR