Eric the concern here is that you will need a speed control switch that will be rated for both ceiling fan motors.
Dimmer fan switch wiring.
If a rewired switch is causing a circuit breaker to trip there is most likely a dead short between a neutral and hot wire a dead short on the wire to the light fixture or two separate circuits are wired to the same light switch.
How to wire a ceiling fan with a dimmer switch 1.
Disconnect all wires from the old switch by loosening the screws and disconnecting them.
Wiring a replacement dimmer switch.
Further pairs connect the wires to the dimmer switch wrapped the joint with electrical tape.
New dimmers have either a green grounding wire or a green ground screw that you ll have to connect to a grounding source if one is available.
Houses wired with plastic sheathed cable almost always have bare copper ground wires that you ll connect to the toggle dimmer switch.
If the dimmer has a separate wall plate tighten the.
Tighten the screws holding the dimmer to the electrical box.
If you locate this switch then both ceiling fans can be wired from one switch.
If you are installing a dimmer that has a removable knob remove the knob from the dimmer by gently pulling outward.
Then test the dimmer switch and if that works tight fit the unit back into the wall being careful not to twist and bend wires.
Switch off the wall switch as well.
Turn off the power for the room with the ceiling fan at the breaker box.