Okay so I'm having a problem with my 01 eclipse. The belt is slipping, and before I go taking everything apart I'm trying to get a figure of what im gonna have to spend. It seems as though the only time the belt slips is when my heater is on and slowly stops when i turn it off... What im thinking if its the alternator. I've also been noticing that the car is starting to idle irradically to the point of dying..... any input anyone?

 

which belt are we talking about here. The accessory belt? If its slipping then it is not properly tensioned or it is bad and worn

 

Like what TE said which belt are you talking abt, if its one of the acc belts check the tension and inspect the pullies.