A/C and Heater Problem

Shorted heater blower motor or heater blower motor resistor. Unplug them one at a times and check for fuse pop.

Does the fuse blow if the compressor clutch is unplugged ?

Broken heater blend door.

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 !

Hi John,

This should be fairly simple. I have uploaded a PDF file to Filesonic.com that contains both the Power Distribution Diagram for Fuse #64 and the Heater Circuits for your 2000 Ford Focus. You can download this file for FREE at the link below. Please note that if you do not have an account with Filesonic, you can still downdload the file for free, but you must use the "Slower Download" link at the bottom of the page. You will then see a timer running in about the center of the page. Once the timer runs out, it will give you a captcha code to enter in order to start the download. This file will only be available on Filesonic for 3 days, so you might want to save a copy to your computer for future reference.

http://www.filesonic.com/file/3040758464/2000_Ford_Focus_Heater_Circuits.pdf

Once yo have the file, you can clearly see that the ONLY thing that is powered by that fuse is the blower motor. That makes this task very easy.

Most likely, the blower motor itself (or the solid state circuits built into it) are shorted. Here is how we PROVE it before going out and buy a blower motor:

1. Unplug the blower motor connector. Replace the fuse with the connector disconnected. If the fuse blows, then the GREEN/ORANGE wire between the fuse and the blower motor is shorted to ground. You will have to follow this wire from the blower motor back to the fuse block to find out where it is shorted.

2. If the fuse does not blow, then take a test light (make sure it uses an incandecent lamp - the LED type will not work for this purpose) and connect it between the GREEN/ORANGE wire (ignition switch ON) and the BLACK/RED wire at the blower motor connector. Using the blower motor speed control switch, the lamp should not light at all with the switch in the OFF position. Then it should light and get brighter with each step as you move the switch toward the HIGH position. If this all works as described, then we have just proven that all of the circuits are good and that you need to replace your blower motor.

3. If anything does not work exactly as described, tell me what it is doing that is different, and we can continue diagnosis if needed.

Hopefully, this is all the information you need, but if you do need anything else, please let me know.

Please also remember to take a moment and rate my service through the FixYa web site.

Thank you for your patronage,

-Dave (dttech)

The blower motor resistor is located within a foot of the blower motor in the duct that the blower motor blows into. The resistor is actually cooled off by the blower motor blowing across it. It has a wire harness that connects it to motor & fan switch. It is held in place by 2-4 retaining screws. Disconnect wire harness,unscrew retaining screws then lift out. Reverse order to install.

Check resistor behind the glove box, take glove box out should be green in colour. Have seen these burnt ot before, should replace the wiring loom and resistor. Not expensive.

If it doesn't blow at all, and/or you only feel a small amount of air coming through the vents (not forced), it may be the blower motor switch (resistor).

Hope this helps.

You need to replace your blower resister.......... The blower resistor is located behind the glove box in the back left corner, follw the wiring harness to the resistor. there is one screw that holds it in place ( a little hard to get to ) unscrew and remove from connector. part is $15 but call different dealers because they price differently. PS squeze the sides of the glove compartment to drop the glove box down
I hope this helps you and please vote on this solution

I believe there are TWO fuses for the heater blower. One for the lower speeds and one for the high speed ONLY. REcheck the fuses or refer to the owner's manual for the location...

no heat or no blower. HUGE difference between those two symptoms. Clarify