By "removable face" do I understand you have an aftermarket radio? Many of them use tiny incandescent bulbs that eventually burn out and leave part of the display back lighting dark.
The air conditioning runs in defrost mode so the AC compressor is putting more strain on the belt. Check that it's tight as suggested previously.
There are two headlights built into each bulb. There's the low beam and the high beam. When one burns out the other one will still work.
Caradiodoc
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Thursday, February 3rd, 2011 AT 8:36 PM