There should be several black wires feeding into your exhaust fan unit. These wires carry the current to the fixture and must connect to the correct wire on your exhaust fan. Typically, each function of your combination exhaust fan unit will have a separate electrical feed. These wires on your exhaust fan unit are usually color-coded.. Supplies You'll Need To Wire An Exhaust Fan And Light On Separate Switches. 12/3 Cable - The bathroom fan needs 12/3 wiring from the housing to the switch in order to for it to use two separate switches. 12/3 wiring includes two hots (black/red), one neutral (white), and one ground (green/copper).; Double Toggle Wall Switch - These double switches will have two toggles so you can separately.
Breez: Ventilation Fan with Light and Heater Instruction Guide; Ask the Electrician: Bathroom Exhaust Fan and Light Electrical Wiring; Home Improvement Stack Exchange: Wiring in a Bath Heater,Vent, Fan Combo with Power Source Coming from Ceiling; Home Improvement Stack Exchange: Wiring Bathroom Exhaust Fan With Heater. How to wired or separate your exhaust fan and light fixtures in your bathroom.