Lighting, Light Fixtures, Ceiling and Exhaust Fans - Bath fan/light combo switch wiring

I installed my bath fan/light combo and ran a new 12-3 cable to the light switch. I took out the existing 12-2 cable. I want to repalce the single light switch with a combo switch (2 single pole switches on one switch.

When i opened up the existing switch I found 3, 12-2 cables coming into the box. Here is what the wires looked like:

All 3 white wires were attached witha wire nut together, 1 black wire was attached to the switch, and the other 2 black wires were wire nutted together and then pigtailed to the switch.

My new cable has a white , a black, and a red. I'm confused about the new wiring and when I attemped to hook it up, when i tried to turn the circuit back on it tripped the breaker back off.

Any help would be gratly appreciatted.

Thanks

Why did you attach a white wire to the switch? None of the others were attached to the old switch?

Connect all the white wires together. Connect the pigtail from the original two black wires to the side of the switch with the tab between the two halves. Connect the black wire to one switch and the red wire to the other switch. Connect the ground wires.

When I connect the grounds together do they have to be connected to any screw or can they be capped by themselves.

Thank you for your help. i guess I was just thinking too hard.

The device (switch) needs to be grounded as does the box, if it is metal.

The box is the existing box from before. How do I tell if it is grounded and then how do I ground the switch

Take all of the ground wires and connect them with a wire nut to two pigtails. Connect one pigtail to the box and the other to the switch.

Alternately use a wire wire designed for ground wires that has a hole in the end. Leave one bare ground wire twice as long as the other and have it extend through the wire nut. This bare wire acts as one of the pigtails.

racraft I wired as you described and turned the circuit back on. THe fan comes on and works fine, the light does not come on at all, and another light (I believe downstream from the bath fan) does not work now.

I will check the light bulb tomorrow morning, but it is a brand new bulb.

Any ideas what I'm doing wrong.

Thanks again for all the help.

Yes, you wired it wrong. The black wires are improperly connected. Go one cable at a time if you have to and figure out what wire goes where. This is not difficult. it is straight forward.

Yes I put the pigtailed blacks to the wrong screw. The black and the red wire coming from the fan/light combo should be on the same side of the switch, correct.

The black and red coming from/going to the fan and light need to be on the same side of the switch, the side with separate terminals, not with connected terminals.