Check your fuse boxes.
It is likely the duct work how ever it can be the fan has come off the fan motor
Replace it. This is probably a sign of badly worn bearings that make it difficult for the motor to spin.
The back up lights on an E350 Ford Econoline Van won't work if the fuse has blown, the bulbs are bad, or the wiring has become disconnected. The reverse sensor also controls when and if the lights turn on.
Several things could cause the Ford vans rear air to not blow. There could be a blown fuse to the blower motor. The fan control could be bad, or the motor could be failing. Also there could be a wiring problem, or the hose from the blower to the vents could have a hole in it, diverting the air.
Because its broken
Does it turn over?If so, check for fuel and spark
Blower Motor Resistor is bad. 20.00 part at AZ.
Replace blower motor resistor usually located in the duct work or out in engine compartment in ductwork by heater motor.
fuse or relay most likely
Check/ replace the blower resistor. Located in the duct work under the hood. Follow the wires from the blower motor to a plug on the duct work. This is the resistor
I would look into the blower motor resistor module