What will keep heater fan from working( both fuses check good)?

ooh that is and oldie....

the heater blower fan is dead, ?
this car is wired (im looking in alldata dot com now)
gets 12v power from the IGNITION at all times. so there is no
blower fuse. (if the fan shorts, the engine fuse blows. and engine dies.
the current passes thru motor, and then to the dash speed switch
and on level 4 there is no resistor, so must run, here, (does it?)
then the switch is grounded.
so if engine runs.
and speed 4 fails, it can only be.
1: bad ground to switch.
2:bad wires.
3 :bad switch,
4: bad fan, (hot wire fan does it work,. yes, good its good.

id put my DMM across the fan , turn it on, and if 12vdc is across said fan, and it dont blow, its a bad fan.
if the low side of fan is not 0v, all times. the ground is bad.
if the 12v never reaches the fan, then the path on that side is bad.

The brown wire at the speed switch is the power wire. Powers is then directed to the blower motor resistor throught the orange, lt blue and yellows wires. The blower motor receives power through the orange wire. Check for power at the fuse with the key on. If there is no power the problem could be the ignition switch or the wiring in between the switch and the fuse block

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

the cab heater fan?, there can be 4 fans on some cars.
front condenser, 2 on rad, and 1 in cab heater box.
the cab fan? does it fail on high too?
it has a switch, (marked fan speed)
the switch is bad ,if low speed are dead. and high are good.
or wiring to it , the motor or the fuse.
even a cracked fuse, change the fan fuse to a new fuse.

Hello,
You may want to try your fan on all speeds. If it will work on high, you have a bad resistor for the fan motor. ( high speed doesn't go through the resistor ).
If it doesn't work on any speed, I would check the following;
1. Make sure the fuse isn't blown for the fan blower motor.
2. Check, or have checked the wires between the fan control switch and the fan blower motor.
3. Have the fan control switch checked.
4. Have the fan blower motor checked.

I hope this helps you.

1-4 speed are the blower motor resister . It controls all 1-4 speeds, also it's under the passanger side dash around fan, the 5th speed runs off a fuse the is located in the fuse box. It's one of those square fuses , not the relays but fuses. The resister will run $15 and fuse $5 . Good luck. I have replace these before

Not sure on this vehicle, but you may have a bad resister block on heater housing that control fan speeds. If not, perhaps the fan speed switch went out in dash.

it could be the fan motor, the resistors that control the speed or the switch as well as a loose wire

could be the resister tht controls the 4 speeds. It's in te plenum case to keep it cool. Or blower motor is failing

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

your speed switch located in heater box usually one wire to it in passenger feet area above "TOES" usually you loose 1 or 2 speeds on fan but it is unplugged or completely cooked good luck!