Sounds like the connections are marginal. Turn off the power, and examine the connections. They should be nice and tight with plenty of clean copper in contact. If this dimmer has stranded wire leads which are connected to solid wires with wire nuts, remove the wire nuts and take a look. If they are messy, cut off the exposed ends of all of the wires and re-strip them. Stranded wires are difficult to strip well without a wire stripping tool. The solid wires should be stripped to a length of about 1/2 inch, the stranded wires should be about 5/8 to 3/4. Now take your stranded wires and twist them like with your fingers so they resemble twisted rope. Then twist the stranded wires around the solid wires with your fingers, just once or twice around. The ends of the stranded wires should be nearly even with the ends of the solid wires. Now add the wire nuts. Twist them nice and tight by hand while holding the pair of wires together at the base of the wire nut. If you have weak fingers or the wire nuts have a fairly small outside diameter, you can use pliers to twist the nuts a little tighter. No bare wire should be visible beyond the base of the wire nut. Make sure that everything is tight by trying to pull off the wire nut and by trying to pull out each wire individually. It's also a good idea to wrap up the wire nuts and a bit of the wire with electrical tape. Good luck. Thanks for using FixYa, Al Kupchella
Answers & Comments
Sounds like the connections are marginal. Turn off the power, and examine the connections. They should be nice and tight with plenty of clean copper in contact. If this dimmer has stranded wire leads which are connected to solid wires with wire nuts, remove the wire nuts and take a look. If they are messy, cut off the exposed ends of all of the wires and re-strip them. Stranded wires are difficult to strip well without a wire stripping tool. The solid wires should be stripped to a length of about 1/2 inch, the stranded wires should be about 5/8 to 3/4. Now take your stranded wires and twist them like with your fingers so they resemble twisted rope. Then twist the stranded wires around the solid wires with your fingers, just once or twice around. The ends of the stranded wires should be nearly even with the ends of the solid wires. Now add the wire nuts. Twist them nice and tight by hand while holding the pair of wires together at the base of the wire nut. If you have weak fingers or the wire nuts have a fairly small outside diameter, you can use pliers to twist the nuts a little tighter. No bare wire should be visible beyond the base of the wire nut. Make sure that everything is tight by trying to pull off the wire nut and by trying to pull out each wire individually. It's also a good idea to wrap up the wire nuts and a bit of the wire with electrical tape. Good luck. Thanks for using FixYa, Al Kupchella