have you checked the fuse if so then you will need to replace the resistor for the blower hig and low dettings have you checked the fuse do you have 12 volts to blower if so then you will need to replace the resistor for the blower replace the blower motor
check fuses,see if ones blown check power at blower, don't forget the fan switch ,there famous for going out.
Chack the speed control switch and the resistor that controls the speed of the motor
The fusebox which controls the blower motor is under the hood up by the firewall.
The blower is controlled by the blower switch, blower resistor, and relevant power relay.
Blower switch and connection had a melt down.
If it has separate blower speed controls for the front and rear, it has separate resistors. Blower speed resistors are mounted close to the blower motor it controls for cooling purposes.
Common causes, blower motor resistor, blower motor, wiring or controls
Heater blower resistor is what controls the low medium high speeds...
the blower resistor controls the fan speeds
Ignition switch worn out and needs to be replaced? After 20 years
When you beat the blower motor, you are probably shaking the blower resister. The resister is what controls the blower speeds and is probably bad or loose.
On my 1989 you first remove the engine coolant reservoir as the blower motor is right behind it. Disconnect the two wires, remove about 10-12 screws around the motor. Then twist, turn, and wiggle the motor out. It's a pretty tight fit so it won't be the easiest thing to get out.