Disconnect the negative battery cable.
it is on the firewall and difficult but not impossible to get to and replace.
The blower is controlled by the blower switch, blower resistor, and relevant power relay.
If there is current going through the wire to the blower switch, try bypassing the switch with a jumper wire. If the blower motor works, then replace the switch. If the blower motor does not come on, then you probably need to replace the blower motor.
replace the switch.
If your blower is working on some speeds but not all, more than likely the problem is a defective Blower Motor Resistor Pack. The switch rarely goes bad. Just a thought.
replace the blower motor switch
The blower motor is drawing to many amps, replace the blower motor.
Your blower switch sensor is out. Replace it!Then all the speeds will work
Check to see if you are getting power to blower motor - if so replace blower motor If not check fuse, switch, resistor pack.
Replace fan switch.
Change blower fan control switch in the dash
take the old switch out, put a new one in