<VV> Headlight problem

[Grant Young]

This problem is actually on my '62 T-Bird, but have not gotten anything useful from that group, so I thought I would try this group since the wiring should be very similar. I have low beams, but when I switch to high beams, the driver side lights both come on, but both the lights on the passenger side go out. I have changed the dimmer switch and checked that the wires are not open or shorted (as far as I can). Thanks for any advise other than to buy another Chevy (I have one of those too). 
Grant