well you could just turn the heater off heater blower
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If it is a car heater then check your coolant level. the heater is driven off a heat converter that is fed by the radiator system. When the coolant fails to pump round the radiator system the car internal heater doesn't work. Driving without coolant in the system will result in the engine overheating and seizing.
First check the coolant level, a coolant leak would cause a heater to stop working- assuming you mean the blower is blowing but it isn't hot. A stuck thermostat will also cause you problems with your heat.
Fuse, switch, speed resistor or motor.
your heat comes from your heater core which draws heat from your engine coolant so if you have no heat and the blower is still running then there is a coolant level problem as in none which then would cause the mottor to over heat and quick
most likely your heater-core went bad. if you car runs perfectly fine besides having heat. if you car gets up to normal temperatures, doesn't over heat. the fan blows, but just blows cold air. then it is the heater core.
Heater coil
Sounds like heater core is leaking, replace heater core or bypass
Unless your van has some unusual heating system, the heat going out could mean that you are totally out of coolant, or your thermostat may be stuck closed. If you have a normal heating system and your heater is still blowing air, just not hot air, it could be those two things. Is the van having any other problems?
OK, did the blower motor actually just stop, or does it still blow but no heat?
To stop it from blowing up.
there is a short somewhere in dash or heater, you need to fix that to stop fuses blowing
Could be,blown fuse, bad blower motor, bad switch, bad resistor,
Is it blowing cold air only or not blowing any air at all.