Could be a bad blower motor, or, look to the blower motor resistor mounted on the engine firewall on the passenger side near the top of the firewall inside the engine compartment. It will have five wires going to it. It is likely either burnt out, or the wires have shorted at or near the resistor.
The heater blower motor is on the interior passenger side. It is kind of a round shaped housing facing the floor.
30 amp fuse in fuse box.
On the inside of the firewall, below and behind the glove box.
Right side under the dash.
It's located behind the glovebox, on the passanger side of the dash
check coolant level
Under the dash, far passenger side.
It's located behind the glovebox, on the passanger side of the dash. How hard is it to get to the fan motor?
The blower motor if failing and pulling to much current.The blower motor if failing and pulling to much current.
Inside the HVAC housing, under the dash on the passenger side.
Check relay, fuses then control head.
Check the blower motors ground and power in the truck and the blower motors resister......