My bathroom light switch is a pullcord with on/off and a red light. I wish to replace it with a plain pullcord, when I tock the old one off there are 2 black, 2 red and 2 earth wires all connected to an individual terminal. The problem is the new one only has three terminals, L1, L2 and COM. the earth terminal is on the base. Which wires do I connect to which terminals?
the old switch sounds like the type used for showers, but if only used for lights then you need to join the 2 blacks together in a connector block ,put both earths together in earth term. in back box.
fit one red into common term. & other red into either l1 or l2, leaving other one empty.
you have a 'double pole switch' ie. it switched live& neutral.
your new one does not switch neutral so the two blacks go together in a spare terminal 'chock-block' in the switch box , the two earths go together in the fixed terminal in the box.
The reds go one to 'Common' term. other to L1, L2 is not used (you have a two way switch).