I have a 3-/4- way switch set up for a ceiling fan/light. I want to control the fan and light separately. I have 12-2 into the first switch location, then 12-3 to switch #2, 12-3 to switch #3, and 12-3 to the fan. I have a combination switch/3-way switch that I am not sure if I can use. I want to know if I can control the fan and light separately from location #3 using the combination switch. The only power into the box at this location is the 12-3 from the 4-way switch at location #2.
You can not do it the way the cable are currently run. You must run the fan and the power cable into the same switch to make it work. The way you have it wired now you only have switched power available to the fan/light.