Heater stays on hi havc won't turn off all fuses good

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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.

according to the service manual there is no separate fuse for blower. If blower does not work at all check a/c fuse if good it could be the fan motor has built in resistor and can easily be bad I hope this helped and not made things worse Mike L.

Check your blower motor resistor connection.Turn switch and fan on then wiggle the resistor pigtail fan should turn on if not replace resistor.These get to hot and usally melt the pigtail and loose their connection.

The three most common problems for heater fans are

1. Burned-out blower motor resistor. This is usually located on the engine side of the firewall. Sometimes one section of the resistor is burned out but others are still good, so the blower only works on the highest speed settings. If you have a burned-out resistor, check the blower bearings to make sure they are not stiff and causing the motor to draw too much current.
2. The blower is actually working, but either the intake vent is plugged (I've seen vehicles with the heater core completely blocked by dirt, leaves and insects that came in through the vent), or the heater door is stuck closed.
3. The motor bearings have gone bad (see # 1). This can cause the fuse to blow, although the resistor usually fries first.

I'm not sure how your car's cabin environmental control system is fused. Check any fuse that might apply, such as Vent/AC, HTR, FAN, etc. Generally you can identify the state of a blade-type fuse by inspection without removing it. If you have a blown fuse, check the blower motor before wasting money on a new fuse that will probably blow. Like any fan, it's supposed to turn easily, and there should not be any roughness or side-slop in the bearings.

Hi I've seen this problem many times. since you've checked the fuse I'm going to assume that your wireing is in good condition. I would say that you have a bad blower motor resistor. The resistor is what controls your fan speed. If the resistor is bad your fan will not start. The other thing you can ckeck is to see if your fan is still in good working condition. Just apply battery voltage to the pins on the blower motor where the connector is. If the fan starts then the fan is good and the fault is in the resistor.

Check heater fuse.
If fuse good - could be a failure of the blower fan motor or blower control switch.
If fuse bad - bad blower fan motor could have blown the fuse.
DO: check fuse, then blower motor.
Pricing: new blower motor: Duralast PM270 $43.99
new heater control switch: Duralast SW229 $46.99 (without
A/C).
I'd expect your blower resistor to be good - when they fail, the blower only will work on HIGH setting.

There is a good chance that the wire harness has burnt out or the blower speed regulator. The other place that can cause this is a the blower switch it self has burnt out also due to the high current drawn by the blower.
Start with inspecting the switch first and then work your way to the blower resistor and harness. If the resistor has gone bad, replace the harness also. Oh and my bad and check the fuse and relay to your HAVC system.
Thank you for using fixya and Auto Zone should have the parts needs to repair your blower issues with the instructions to get the job done with common tools.

The heater control,where you turn it on,and off,pull it out,it is most likely burned up where the connector attaches to the switch,and the connector,will most likely have to be replaced.

youve got a short prob right at the switch in the dash,unplug the switch and if it shuts off then replace it,if not run new wires form the fan motor too the battery thru a toggle stwich

There are two fuses for the fan. One is probably a 20 Amp in the fuse panel in the cab and marked "Heater". or "Heater/AC" The second is under the hood may be marked Heater, Blower, or Fan and should be 30 Amp. The one in the cab supplies switched 12 volts to the fan speed switch. The one under the hood supplies the 12 volts to the relay. The relay is normally energized by the 12 volts through the 20 Amp fuse in the cab and through the switch. I think you find that the fan has the normal speeds except for missing HI with the underhood fuse removed, and will turn off with the ignition that way. There is no hazard in operating it that way but you may want to replace the resistor/relay assembly before it gets too cold. The relay is a pretty trouble free device in most cases, maybe you can find a deal on a good one at a junkyard.

The whole idea with the relay under the hood started back in the Sixties believe it or not. There is considerable voltage drop in the wiring between the fan switch and the blower fan motor. By adding the relay under the hood right next to the motor, the voltage drop was reduced, both by the shorter wire, and by using heavier wire to boot. The motor gets really close to the full system voltage when the relay is closed. In your case where the relay keeps the fan running, it can drain a battery rather quickly too!