The headlight bulb will have 3 connections - 1 for the main beam, 1 for the dipped beam and 1 for the earth connection. If you have neither head or dipped beam then this earth connection is the one to look at. It directly connects the lamp body to the cars metal bodywork. You'll really need a 12v tester lamp though to find out which of the 2 cables carry the electrical current from the switch - haphazard messing about normally just blows fuses.
John, December 2007
