ban-all-sheds, read the post again, see if you change your mind.
he said he wants to join 2 sets of christmas lights , in short if you do that they wont work, since they are wired in series
Jim_Connolly
you can not do what you are thinking / suggesting, as to add another set of lights to the existing set means there will not be enough current to operate all lights.
Its like you have one orange, you mate comes along, he wants one, but there is only one orange, only fair thing is half each, that is what your lights will do
you have 3 options,
get a new bigger and longer set of lights
get a bigger and lomger set of lights and plug them in as well (as well as your short set)
by loads of lights and plug them all in
either way they will all have to be plugged in, in doors