I had a similar problem with my 57 chev. To make a long story short I fried the wire from the front right parking light to the switch. There seem to be no reason for this to happen. I replaced the switch and re wired the lights and preyed they now work with no problems. Why this happened is beyond me so maybe Stuart is right it was a freak thing. One explanation was there was short somewhere and it chose that wire to run all the way to the switch or the switch went bad... my 2 cents here ... Peter
