I'm replacing a fan in a bathroom. The setup I have currently cannot be changed with new wiring. I can add pigtails but I can't run a new 3-wire cable through the chase. Power supply runs to the fan box first. The old combo fan and light were independently operated on a double switch. 2 separate 2-wire (plus ground) cables are running from the fan box to each side of the double switch. I don't know how the old fan-light combo was wired but the double switch had the grounds tied together in the switch box (but not grounded to anything); 2 white wires hooked up to two black screws on the right side of the double switch; and 2 black wires hooked up to the brass-colored screws on the left side. There were no other wires in the switch box and no jumpers or pigtails there.
The fan that I purchased is the Delta Breeze Green Builder with combination LED light, fan, and automatic humidity sensor GBR80HLED. The fan comes with three pairs of wire and a ground. One pair is white and black labeled power. One pair is white and blue labeled mode. One pair is white and red and not labeled. Instructions do not show how to wire with power to fixture first. They show using either three or two switches connecting blue to blue and red to red, neither of which I have in my cabling.
I would like to use existing wires and set it up so that mode (humidity sensor) is always on, one switch controls light, and one switch controls manual on fan for odors. Help with a diagram?