96 tercel, blower motor only works on high speed, checked all fuses, and relays, replaced resistor, still only high speed.

94 CHEVY Silverado ????,heat/ac fan not blowing. K1500?????? Hear clicking when selecting l'm, SET high but not blowing! WITH AIR OR NO A/C? FIRST IS FUSES, MAKE SURE THE BLOWER FUSE IS NOT BLOWN.
EASY NO? CHECK ALL FUSES FIRST. ON ALL ELECTRICS FAILING OF ANY KIND.
BAD FUSE, BAD WIRINIG , BAD CONNECTIONS. OR EVEN BAD RELAYS TO THE BLOWER OR BAD SWITCH BLOW.
THE OLD CARS , HAD A SPEED BLOW , RESISTOR BLOCK
THAT FAILS ON ALL SPEEDS BUT HIGH, SO ITS NOT THAT.
OWN A VOLT METER????
HERE IT IS, ANY OF THIS CAN FAIL THIS OLD
WE USES A VOLTMETER TO FIND THE POINT OF FAILURE.
A SHORTED BLOWER MOTOR CAN BLOW LEFT SIDE TOP
FUSABLE LINK.RIGHT FUSE BLOWN MAKES THE CONTROLLER DEAD.

The blower motor relay is energized when the Blower Motor Control is set to the High position. This removes the blower motor resistors from the circuit and battery voltage is then applied directly from the HVAC BLO fuse (RH IP Accessory Wiring Junction Block) to the blower motor though the relay switch contacts. The blower motor then runs at high speed.

HVAC Blower Controls Circuit Description
The blower motor is a variable speed motor. The motor operates at a higher rate when voltage is increased to the maximum level.
The blower motor resistors reduce the voltage supplied from the A/C FAN fuse (LH IP Accessory Wiring Junction Block) when the blower control is set at low and medium speeds (speeds 1-4). The blower motor relay is energized when the Blower Motor Control is set to the High position. This removes the blower motor resistors from the circuit and battery voltage is then applied directly from the HVAC BLO fuse (RH IP Accessory Wiring Junction Block) to the blower motor though the relay switch contacts. The blower motor then runs at high speed.

I looked at 05 avalanche 1500--automatic hvac. The blower fuse is hot all the time. The fuse has an input leg and output leg, even if the fuse is blown, the input leg would still have voltage. If no voltage, you could use jumper wire connected to voltage on the output side of fuse cavity to see if blower would work. If you use jumper, use an inline fuse.
Yes, it could be something wrong with fuse box or wiring circuit?

Replace the blower motor. The brushes wear out. Any autoparts store has them. About 100 dollars

Test for current to motor. If none you have either a bad fuse, bad switch or bad wiring. Nothing else left.

power flows from fuse to blower motor relay. From there it flows to blower motor. Blower motor receives ground from two different places depending on which speed you choose. If you choose high speed, it gets ground through the blower motor high relay. If you choose any other speed, it gets ground through the power transistor below the right side of the dash. The power transistor regulates fan speed by pulsing ground on and off based on the speed you've set. Power transistor is most common failure point in these systems

The resistor bank is bad for slow speeds, the switch is bad for high speed. In your test, you have voltage, but the switch wont carry the amps, to run high speed. Open circuits will not blow fuses. Replace both switch and resistor bank for all speeds. Make sure to clean leaves and trash from fan housing and see if fan spins freely.

In the beginning you should check for voltage and ground.
The 50amp fuse marked AC powers the blower motor and the motor is grounded.
The high speed relay bypasses the resistor. So you should have power coming from the fuse and thru the high relay. Then the resistor for the other speeds gets power from the heat and ac control module which also controls the blend doors.
You may need a shop manual or repair book to get the diagrams.

if fuses are good, check for power at blower motor, when truck is running and a/c on. the resistor and the switch provide ground, so the blue/white wire should have power, and the blue/black wire should have NO power, if it does have power, then most likely the resistor is bad. if it has no power and the motor doesnt run, the motor is bad.

Hello,

I have a 2003 Chevy Cavalier. The HVAC airflow dial only works on high setting. We checked the fuse and it's o.k.

What now?  Any estimate as to repair cost? 

Thank you