You need to go over and check all of your grounds. Every single one on the car.
Get yourself a 9004 headlamp bulb, a socket for it and some test leads. Solder it up to make a heavy duty test light. I also highly recommend buying a power probe tool.
Then go over and test every 12V power into the trouble components and see if they can light the bulb. Test it between the components power and ground and also the battery negative itself.
If the bulb is dim or not lit between the components power and ground then it could be high resistance causing the lack of full function.