And many people are asking the question, #Why? Why did God allow this? Why all of this if there’s a loving and powerful God? Why do bad things happen to good
by Matt Slick God allows bad things to happen because it is his will to allow bad things to happen. Ephesians 1, says that God works all things after the counsel of
the instruction sheet that came with the ceiling
fan probably indicates which wires are for the lights and which wires are for the fan.
Black wires if installed by someone knowledgeable are the hot leads, and should be routed to the wall switches before coming back to the fan and its d with that information, you should hopefully be able to connect it up so that the wall switches function as they were originally intended.
Based upon the fan running slow when the lights are on makes me think you may have a poor connection or you may have the lights and fan connected in series,but not being there to see what it all looks like and which wires are hot when their respective switches are in the "ON" position, it is hard for me to make an assumption as to what wires are erroneously connected or might have a weak splice within the wire nut(s) used for connecting up the fan and lights.
If the instruction sheet doesn't tell you which colored wires need to be connected to the switched inputs, why not bench test the fan light using a test extension cord setup to determine which color wires are for the hot input and which colors are the return lines for each function. I believe the smaller blade portion of a a wall outlet is the "HOT" lead (someone in here is sure to correct me if I have that transposed... lol).Mark and label the wires with tape, so that when you are up on the ladder, you will find it easier to them up correctly.
The lights won't care which direction the current flows, but the fan motor may.