after running the 14/2 wire for 4 50w halogen pot lights in series on
1 switch on a 15A breaker, I installed 1 pot light with a dimmer switch. This worked wonderfully well and I can dim the 1 pot light with the installed dimmer switch. After I installed the remaining 3 pot lights, the 4 pot lights dimmed even if the dimmer switch was not lowered down. What could have caused the lights to go very dim and cannot be controlled by the dimmer ?