Blower motor resistor

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25AMP FUSE BLOWS?
PULL THE AC COMP CLUTCH WIRE, THEY LOVE TO SHORT.
THE FUSE RUNS CLUTCH AND BLOWER SO I CALL CLUTCH ELECROMAG SHORTED
SAY WARM !!!!!
and sure doing that kills AC defrost mode. no clutch.

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.

On Nissan vehicles, the blower motor gets power from the fuse box, and the resistor and fan speed control provide the ground circuit.
So you should be able to ground the motor and make it run if you have power going to it. Then you would need to check the resistor and fan switch. The high setting bypasses the resistor.

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.

I would disconnect your blower motor resistor then try fuse again, if it does'nt blow then it is either blower motor or resistor,these resistors are common for going bad/and or blower motor. Good luck let me know if you need more info or if this didn't fix it, I will research it more for you

When the blower works only on the high setting its usually a bad blower resistor which is right near the blower motor. now you say it would always blow high regardless of the fan speed setting that would indicate probably the climate control unit or a connector problem somewhere. finally it not working at all may be the climate control unit or connection went bad even further. it might have a blown fuse or a bad blower motor in addition to the climate control unit or connector problem .check for power and ground at the blower motor. the power is supplied from fuses and may have a relay also. the ground is supplied from the climate control unit and goes through the resistor to control the fan speed. good luck

I was able to repair the resistor for $2 without soldering. Also, perform maintenance on your blower motor to prevent thermal fuse from blowing again.

There are only a couple of things that could cause this issue, and I would start with the simplest thing first, and that is to check your fuse panel. Your blower will operate only on high because it is wired to do so on the number 4 setting as it bypasses the blower motor resistor. If the fuses are good, then the blower motor resistor is the next step, and this can be found close to the blower motor, as the blower motor, when on, cools the resistor, when the resistor gets old and to hot, it will blow, thus causing your fan to only work on high. If the resistor is good, then the last thing that you would check is the fan selector switch. I seriously doubt that it is the switch, it is usually the fuse, or the resistor.

Clear out the dust on the dial and slide control first.
MOVE these control back and forth and sensor for broken linkage and connecting rods.
If these are able to move smoothly then turn the back and froth and monitor for the flap / defector blending valve movement.
Pass a ShopVac to clean out all the dust.
==== The resistor pack for the blower motor can fail over time.
Check loose connector on blower and resistor pack around the firewall.

Please keep me up to date on the fix via email.

If the fuse is blown for the blower then there is a short, that is not an answer, go to the blower and check to see that the blower motor connector has 12 volts to it when the blower is set to high speed on control, if it does then u need a new blower motor, if it doesn't then the control switch is defective or the blower motor speed control resistor is defective.