The blower motor is on the passenger side of the vehicle. It is under the glove box at about foot level. Frequently the hot wire that goes to the fan gets hit by someones foot and it makes it short out. Check the hot wire going to the fan motor.
Blower motor located at the passenger side under the dash. Probably the blower motor but you need to check the blower motor resistor and the plug to the resistor. A common cause is the plug tends to melt & short out.
blower motor has a short. replace blower motor
Check the resistance on the blower motor.
most likely cause is one of three relays for the blower motor, usually located on the firewall under a plastic covering or near the battery If you do not use the blower motor very often like your car sits for a few weeks mositure gets in the blower motor and causes rusting which can cause your blower motor to lock up. Best suggestion is to run you air conditioning unit on high for about half an hour every once in a while.
Need to replace the blower motor resistor which is located just under the passenger side dash. 2 bolts on either side will remove it. Cost of replacement resistor is about $20.
When the blower motor stays on it means there is a short to power, or the relay is sticking. 99.9% of the time the relay sticks. I belive on the 2004 silverados the blower motor relay is internal to the blower motor resistor. Try to find an auxillary blower motor relay and if there isn't one then replace the blower motor resistor.
Check all the fuses and relays first. If they all appear to be in good working order, then you'll have to get to the blower motor. Could be a short or the motor could be bad.
the reason blower does not work on all speeds, is the fan blower motor resistor. The resistor is a 4-5 step series circuit, 1 resistor is added for each reduction in speed. If one burns out then so will all speeds below it. The "high" circuit usually has a separate fuse and bypasses the resistor altogether.
The motor drives the belt :witch drives a plate witch when engaged drives the wheels (short version) :with drives a pulley that turns the blower (short version)
Short in the circuit somewhere. Try unplugging the blower motor, closing the circuit with a test lead or test light, and seeing if it blows then. If not, the problem would seem to be in the blower motor itself.
The motor drives the belt :witch drives a plate witch when engaged drives the wheels (short version) :with drives a pulley that turns the blower (short version)
there is an electrical short in the blower motor, making wires overheat. replace blower motor