L= Low beam
H= High Beam
C= Common
And in case its of interest I proved this using a multimeter set on ohms, L to C was 1.1 Ohms, C to H was 0.8 Ohms and L to H was 1.5 Ohms, yes I know theres 0.2 ohms gone missing but I assume this is the resistance of the leads and connections playing a part as electronics multimeter never seems perticularily accurate at very low resistances.
Hope this helps someone fitting sealed beams in a hurry !!
