Mitsubishi Repair: fan not working, radiator fan, radiator

Question
well my eclipse 98 gs has to fans in the radiator and only one turns on and the car gets over heated the one in the passenger side don't work what could be the problem and it only turns on when ever it wants to how can i fix it

Answer
Jesus,
The two fans you are referring to are your main radiator fan and the auxiliary A/C fan.  That fan only comes on when you A/C is turned on.  It won't come on just because your engine is hot.  Your mechanic can better diagnose the main reason your engine is overheating.  It's not because of your fans.
Good luck!