You have a loose connection. So when you hit a bump the connection makes contact, turning on the blower.
The blower on the back heater may need to be replaced on the 2000 Ford Winstar.
you may not have the heater water hoses plugged in
probably the heater core is clogged
cuz ur car wot run idiot
Faulty thermostat. Plugged heater core. Temp blend door malfunction.
heater will not blow on a 1996 ford contour
if the heater does not blow out warm air change the setting.
Probably your thermostat
check you antifreze level if it is low you wont have eat or if you get lots of fog your heater core is bad
The temperature blend door may be at fault.
The heater might blow cold air in a 2000 Silverado because the thermostat is sticking and not changing from cold to heat. The thermostat is usually located in a hose that leads from the radiator to the motor.
The heater does not blow air because it emits infrared rays that have heat molecules within them, thus releasing heat, not blowing it. A heater does not blow air becasue there is no moving air source within the heater. The heater emits infrered rays that cause heat to slowly flow out of the heater.