Recently, I was replacing a fan switch at the ceiling fan on an older ceiling fan. While I had the power off, I decided to try to correct some wiring at the wall switches. The light switch at wall worked fine. The fan switch is one of those round ones where you turn it to the right or left to adjust fan speed and turn to the left to turn off. What was happening here was the fan speed was not being changed, but the light would brighten/dim and then cut off when you turned the knob a certain direction. The fan and light switches are in separate boxes. The fan switch has 4 wires coming in (from House, to ceiling fan, to light switch, blue wire from ceiling fan to control light. Based on the behavior of fan switch, I believe the wiring was as follows 1. Black Home wire, Black wire from fan switch, Black Fan wired together 2. Black Light and Black Wire from fan switch wired together. 3. White Home and Blue wire wired together. 4. White to fan and and White Light wired together 5. Grounds wired together. This is an older switch, so no ground from fan switch itself.
To correct and make fans switch work properly, shouldn't the black Fan wire from #1 been swapped with Black Light wire from #2?