Guy:
As far as I am concerned, 30 cp & 50 cp refer to the brightness of the bulb. Most bulbs of this type say 6 - 8 volts. Are you running a 6 volt or 8 volt battery? Somehow, the new bulbs that you bought received an extra jolt of electricity and burnt them out. I had the same thing happen one spring when I fired the car up for the first time. Never could explain it. Maybe someone else on this forum has had a similar experience or can shed a little light?? on the matter.
Gord
Hi Guy: I believe you are right, the CP is short for candle power. A 30 CP bulb would draw less current than a 50 CP bulb, so the change in CP rating should not casue your new lower-CP bulbs to burn out. But I suspect that your 'fiddling' with the sockets as you changed the bulbs may have disturbed the wiring behind the sockets. I just recently dismantled our headlight sockets so I could see how to replace the existing original 80 year old wires with new ones, and the connections in there were very poor. When I replaced the wires, I soldered the end of the new wire to the connector, not just wrapped around it as was originally done. Wire wraps tend to come loose with the vibrations of the car. I would also check to see what voltage is being delivered at the sockets, making sure it is no more than the Battery's voltage.
Where Are You From? Cumberland Museum, Ottawa, Ontario, Canada