LED bed lights blew fuse

I noticed my bed light wires came apart. I tried to solder the connections using new wires(18g) to extend the length. Every time I turn off the lights on they blow a fuse.

looks like the Lights use 18g wires and the switch uses a larger gauge.

I soldered the positive from the lights to the switch and soldered those two into one wire going into the positive fuse block. same method for the negative.

Am I doing something wrong? The fuse block is connected to the battery using 10g wires.