Chrysler Repair: 93 New Yorker: no radio with lamp on, stereo speakers, running lights

Question
I bought a used 1993 New Yorker.  The previous owner had added stereo speakers and an alarm, both of which have now been removed.  Here is my question:  When I have the radio on and then switch on the headlights, the radio goes off...that is I cannot have the radio on at the same time as the lights.  Any ideas about how to go about diagnosing and fixing the problem?  Thanks!

Answer
Hi Jerry,
I assume this is 'new' LH body New Yorker, otherwise let me know. The only tie in between the headlamps and the radio is the L7 wire (black/yellow) which powers the running lights and tells the radio that you have turned them on so it will shift to the dimmable dial illumination circuit. I would suggest going fuse #2 under the dash to see if the voltage on that fuse drops when you turn on the parking lamps and then the headlamps. Something in those other circuits could be shorting down the voltage to the radio. Is the radio stock?
Roland