1989 240sx electrical problem

[nissan240s_x]

I hav no clue where to start... or even check. my rear hatch windsheild wipers wont stop moving. the switch is not even on and after 2 days it stops by itself and works fine again. i wait about 1-2 weeks and i start my car and they start moving again. my brake lights where working fine but now they dont and i havent done anything to the car. there are alot of other problems too. if anyone has any good tips, wiring diagrams or site i would really appreciate it. HELP!!!