Need to track down what the problem is first. When you say your heater isn't working. When you turn the AC fan on does air come out of the vents? If so your blower is working and the fuse is good. If that is good then check the fluid level of your antifreeze and make sure it is full. Next get the car to operating temperature and turn the heater on high. Then feel the heater hoses going in and coming out of the heater. Both should be hot. If one ins't the heater core is blocked.