[Spridgets] electrical fun!

[ryan.kubanoff at comcast.net]

so back in May i put in a sony stereo head unit into my 74 midget. Its been fine with no problems till Wednesday on my way into work.  I went to shut off my heater fan (it was low 50's)  and a few seconds later the radio dies.  I have constant power from the hazard switch but no display or music.  It was suggested that its grounded out somewhere, how do I go about finding and fixing this problem???
ryan