wa8yxm wrote:
Not odd to me at all.. HERE is the problem or rather two problems of which you have one.
ONE: A wire, (A hot wire) rubbing up against a frame member or brace somewhere has worn through the insulation, sometimes it contacts, and after bouncing down the highway sometimes it does not connect, and again a few more bounces, it connects again.. When it connects pop go the fuses.
OR: you have lost a wire nut behind a fixture and.. See above paragraph.
Note that item 1 can be a wire inside the fixture.
I agree with these ideas and would add one more idea. The problem may be between the fuse and the switch since a new fuse blows with the switch off.