Use this wiring when the source is at the fixture and you want to control the feed to both components with the same switch. Three-wire cable runs from the fan to the switch box and the source neutral is spliced to the white wire and to the fan neutral.
This wiring arrangement allows for lowering the lights with a dimmer and controlling the fan with the builtin pull chain. The source is at the ceiling outlet box and 3-wire cable runs from there to the switch box. The neutral from the source is spliced directly to the white wire on the fan kit and the cable, running it through to the switch box.
The hot source is spliced to the black, fan wire and the black wire running to the dimmer. At the other end, the black cable wire is spliced to one of the hot dimmer wires, it doesn’t matter which one. The other dimmer wire is spliced to the red wire in the switch box which is spliced to the blue, light wire at the other end.
This diagram illustrates the wiring for a Cooper gfci/switch combo device wired to protect a garbage disposal. With this arrangement a receptacle, switch and disposal are protected with the ground fault breaker built into the device.