My ac/heater fan stopped working on all speeds. Both the fan assembly and the resistor under the dash have been replaced in the past. Is there a fuse that controls the fan?

Don't know where you got your info . The heater blower motor electrical B+ power comes from Fuse F 64 a 40 amp fuse . This goes right to the blower motor on the green with orange stripe wire , The black with red stripe wire goes to the switch for high speed . There is Splice 24 that ties into the black with red stripe wire. The splice 24 turns into a black with orange stripe wire . An this wire goes to the blower motor resistor . All the switch does is route the B+ voltage through the different resistors to ground .

Thermal resistor "usually" stops working is because of faulty fan speed switch ???? Totally not true , resistor assemblies fail because of the heat associated with dropping voltage across the resistors , That is why they put the resistor assembly in the air box . Air blows over to cool the resistors . The switch is nothing more then a way to direct different speeds to ground .

Rather then listening to other people ,why not learn the right way to test electrical circuits .
Electric Testing Techniques You Need to Know

Do you know what a wiring diagram is ?
http://www.bbbind.com/free_tsb.html Enter vehicle info . Under system click on HVAC , under subsystem click on heater . Click the search button , then on the link . Use a volt meter an test , don't guess !

Hello, pretty easy fix for this. replace the blower resistor assembly mounted under the passenger side of dash the resistor is held in place with 5.5 mm screws

I assume the blower is not running. The first thing to check is the fuse for the blower motor. This is either in the fuse panel under the dash or on the main junction box in the engine bay.

Next step is to check that the motor is actually getting power. You should be able to access the blower fan assembly from the glove compartment. The compartment door will probably need to be removed, along with some other dash parts. You should be able to see the AC evaporator unit, with the fan assmbly.


It's unlikely but not impossible that the motor has failed. There may be leaves or other garbage in the motor assembly. In any case, removing the assembly will allow you to clean and test it.

The more likely problem however is the blower speed 10W resistor has failed. Look on the assmbly for a removable panel with two or three wires. Remove this panel, and look for a large ceramic resistor. This sits in the air flow to keep cool, and adjusts the blower speed.

When this resistor burns out, the blower stops.

there's a resistor pack for the fan that allows it to work at different speeds. does it work on the high setting but no others? if so, it's the resistor pack at fault. it's mounted on the fan under the passenger side of the dashboard. you may have to pull the glove box down and use an extension to get to it. if it doesnt work on high or at all, try to pull the connector off of the fan under the dash, turn the ac on and check for proper voltage and ground. it should just be a plain old red wire and a black wire. the red is power. the black is ground.

The resistors are in circuit only on the lower fan speed settings.
On the highest speed setting, power is switched directly to the fan motor.
Check fan power supply fuses,
Check power is available to the fan when high speed selected.
If all above OK, apply power directly to the motor to verify fan motor runs- if it doesn't the motor may need replacement/repair.

Ok, first off, check the fuses under the dash. If they're all good, does the blower work only on high speed? If yes, then you have a bad blower motor resistor, which is located under the hood, near the blower motor itself. If the motor doesnt work at all at any fan speed, make sure the wiring harness that plugs into the motor under the hood is clean and tightly installed. If it still doesnt operate, sometimes tapping on the blower motor housing will kick it on, but if that doesnt work, you may have to replace the blower motor. They are available aftermarket, and arent usually too expensive.

BLOWER MOTOR RESISTOR IS BAD . HI SPEED IS DIRECT POWER BUT ALL OTHERS GO THROUGH RESISTOR

The fan generally is located under the dash on the passenger side... while you are there you will notice a couple wires plugged into the side of the duct work near the fan... that's your resister block for the fan speeds... it's likely failed... remove the two or three screws holding it in... unplug the connecter and replace it.

Robert

there is no relay for the heater fan it's a 15 amp fuse and is on the accessories circuit. the reostat is responsible for all 3 speeds .with the key off there should be no voltage to the blower motor whether the fans speed fan switch is on or off. the fuse will be located in the fuse paneleither on the drivers left side in the dash or underneath the dash in the fuse block. you have a short in the harness that is under the dash and most likely it's a bad plug on the harness. your going to have to do some searching but that's where the problem short is... please rate

the blower motor resistor located in the heater A/C panel usualy under the glove box