You have too many problems to just start groping through the wiring harness blindly. You will have to learn the circuits and what the different colored wires do.
Above all you need to get yourself an multimeter and learn how to use it.
Here is a very good tutorial from U tube.
https://www.youtube.com/watch?v=zb7WHaL_dz8
They vary in design but most of them are similar. You can get one from Walmart, harbor freight sears or just about any auto store and $20 will buy all you need.
When you get familiar with using it we will start diagnosing your problems.