Headlights/wipers sometimes don't work
 

Hello I have a 2002 2.2 cavalier, sometimes the headlights and wipers won't work. If i have the wipers on high it'll put the headlights on but no wipers. Sometimes if i put the car in park everything will magically work. Also my A/c is junk. It'll turn on and off repeatedly and jump rpms and drop, it'll drop rpms so low the engine cuts when at a red light. If i put in neutral it will not cut the engine but still go on and off as the rpms go up and down.

Anyone have any ideas? would help alot

Thanks