Lucas SP140 horn and dip switch

[jddevel]

Confused over why I can`t get continuity to ensure operation before installation of my Lucas SP140 horn/headlight/dip switch. I have assumed that on depression I should get continuity between the cable normally connected to H on the ignition switch and that one connected to the horn? I have attached a couple of pictures with it dis-assembled. I assume that on depression the inner copper/brass coloured plate makes contact with the silver/chrome coloured plate. How should this make contact with the cable leading to the horn? If so have I something missing or has the internal terminal ( slotted screw holding the cable in place ) lost something or worn away. Anyone got any advice please?

[Franz Tenbrock]

Hi
you know that the horn is switched against earth
all other lamps are switched on power !

the reason is that the horn has the highest consumption