Heater just stopped working in 1996 explorer what can i look at or what could it be?

Im not sure if you mean the blower is'nt working or if you mean the blower is working but the air is cold so I'll try to answer both, if the blower is'nt working it is possibly a bad fuse, the fuse panel may list it as the heater or it may say blower, now if its blowing but the air is cold it is most likely a bad thermostat, sometimes the heater core goes out but if you havnt noticed the window fogging on the front windshield on the passenger side or smelled coolant in the cab of the vehicle the heater core is probably fine , the thermostat is a common culprit and they are fairly easy to change, one other thing before you go changing anything, check to make sure the radiator is full, with the car cool take the radiator cap off and run the car until it starts to get warm and see if you can add some coolant