Not knowing when the fan motor starts and stops, I would check this-if the blower doesn't run then you hit a bump, pothole, etc. and it runs, its probably the bushings in the motor. The only fix for this is replacing the blower assembly. If the motor isn't manufactured/remanufactured correctly, then the bushings which actually turn the shaft by inducing the electrical field are shot. A simple test is the next time the blower stops, hit the motor with your hand to see if it will start.
There's a short in your main line going to your fuel heater.
Heater blower motor is defective and locked up, or possible short in the wiring.
There is an electrical short to ground in the fan switch or in the blower motor itself.
You probably have a shorted wire going to the motor or switch. You'll have trace the wires and find the damaged section.
not usually!!if fuse is blowing out check for short!!
could be head gasket problem. does your heater work? might need heater core , clogged up. do compression test. or bypass heater core and see if that works.
bottom element is probably bad. another sign of this is that you run out of hot water fast.
Beause there is probably a short/bad connection in the switch, or the blower motor itself
Could be, Low on coolant, A stuck open thermostat, A plugged heater core, A faulty temp blend door actuator,
Space is a never ending area it never stops
The air doors maybe stuck. Or selector switch is not is not operating correctly.
Perpetual motion machines do not exist. There is no machine that will keep on moving by itself without any added power. Windmills are driven by the wind. When the wind stops blowing, the windmill stops turning.