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Ford snr master
Ford snr master, ASE Certified Technician
Category: Ford
Satisfied Customers: 1809
Experience:  14 years at same Ford dealer,senior master and ASE master certified,hybrid certified,SYNC certified,10 year master's tenure
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2001 Ford Focus: Wagon..The Heater Blower Switch..faulty..resistor

Customer Question

I have a 2001 Ford Focus Wagon. The Heater Blower Switch will only operate at the 4 position. All on-line discusions point to a faulty fan resistor. I purchased a fan resistor from the dealership and replaced the old resistor but have the same problem. Even if the resistor is disconnected, the fan will only run at 4. All wiring and connectors look to be in good condition. What are my next options? Replace the heater switch? Is there a relay switch somewhere I should also be thinking about?
Submitted: 7 years ago.
Category: Ford
Expert:  Ford snr master replied 7 years ago.

I have provided the wiring diagram for you to aid in the diagnosis. Most likely the switch itself has gone bad and can be tested by selecting the switch in each position and checking resistance through the switch in each mode. most likely you have a failed switch as this happens occasionally on these models. If the switch tests finbe, please advise me and i will walk you throught he diag step by step

graphic

I hope my assistance helped you and resolved your concern, after accepting the report stays open for further questions, if you need further assistance please ask,

Please click the 'ACCEPT' button to allow me to recieve credit for my work. Positive feedback is always appreciated. If you feel the answer was able to save you significant time and money Bonuses are appreciated & would make my day.

 

Customer: replied 7 years ago.
To test the fan switch, do I need to remove it or can I take resistance reads off the conector going to the resistor?
Expert:  Ford snr master replied 7 years ago.

as long as you can remove the panel itself to access the back of the switch you can unplug the connecter and test the switch while it is mounted. You would want the switch to be in speed position 1 and test the 2 terminals of the black to the black/white wire for resistance, then to check the 2nd speed you would want the switch in setting 2 and test resistance between the switch on the terminals of the black to the black/yellow wire, and repeat the procedure accordingly with the 3rd settting with the black to the black/blue wire as well as the 4th setting between the black and the black/orange wire. You can also jump the wires as mentioned to bypass the switch and see if the blower speed settings work and if they all do by bypassing the switch then the switch is at fault. When checking the resistance through the switch the readings should all be less than one Ohm

Ford snr master and 2 other Ford Specialists are ready to help you
Customer: replied 7 years ago.
Thank you for the additional details. I'll get back to you if the switch checks out ok - otherwise, thank you for your help!
Expert:  Ford snr master replied 7 years ago.
you are very welcome, i am here for you if you need further assistance
Customer: replied 7 years ago.

I am back - The heater fan switch checked out as fine I even checked it with a new switch. Where do I go now if the heater fan switch and the resistor is good? I am still getting the fan at setting 4 but not the other settings. I am assuming that the new resister I installed the other day is good and I have not seen any problems with wiring or conectors.

 

 

 

 

Expert:  Ford snr master replied 7 years ago.
have you tried jumping the terminals of at the blower switch connecter in each setting to see if the blower operates after bypassing the switch?
Customer: replied 7 years ago.

No, I have not tried a jumper - I will need to locate some wire. And will let you know.

 

Thanks

Expert:  Ford snr master replied 7 years ago.

thi test will determin if it is the switch or the resistor, if the blower operates in the different modes when jumping:

black to black/white speed1

black to black/yellow speed 2

black to black/blue speed 3

and black to black/orange speed 4

 

then the switch is bad, if the blower does not operate with that test please let me know and i will have you perform a test to bypass the resistor to see if that is at fault. Even though it is new ,the thermal limiter could have fried and that would render the new resistor inoperable

Customer: replied 7 years ago.

I tried the jumper and the blower only operated on speed 4

 

1 2 @3 settings when jumpered did not operate the blower.

 

Looks like we are back to the resistor - how do you do the next test?

Expert:  Ford snr master replied 7 years ago.

yes, i would tend to think the resistor is bad, since the blower operates we know it is definately not that. What i would want you to do next, reconnect the switch, unplug the resistor and:

 

with the switch in speed 1, at the resistor connecter jumpt the black/white wire to the black/blue wire in pin1

with the switch in speed 2, jump the black/yellow wire to the black/blue wire (pin1)

with the switch in speed 3, jump the black/blue wire (pin4) to the black/blue wire(pin1)

the blower motor should come on with each setting

Customer: replied 7 years ago.

I got the following results:

 

with the switch in speed 1, at the resistor connecter jump the black/white wire to the black/blue wire in pin1 - no blower

 

with the switch in speed 2, jump the black/yellow wire to the black/blue wire (pin1) - no blower

 

with the switch in speed 3, jump the black/blue wire (pin4) to the black/blue wire(pin1) - no second black/blue wire

 

If you use the black/orange wire as the common wire you get the following:

 

4th wire is Black / orange if you jump with Black/white with setting 1 - the blower is on (no for other wires)

 

Black / orange with Black/yellow with setting 2 you get blower (no for other wires)

 

Black/Orange wire with Black/blue with setting 3 you get blower (no for other wires)

 

Is the second set of jumps using black/orange the correct test?

 

 

Expert:  Ford snr master replied 7 years ago.

since it works with using the black/orange(which as you can see is connected to the black/blue at splice S24) i would suspect either S24 to be bad or corroded or loose, or there is an open on the black/blue wire. If you have an ohm meter, please check resistance from the black/blue wire at the resistor to the black/orange wire at the blower motor, it should register below 1 ohm. Please let me know what you find.

My apolagies for the lapse in reply, rush hour trafic was horrible due to the shoppers going to the mall

Customer: replied 7 years ago.

Sorry for the delay getting back to you but I have been out of town during the holidays. I did check the wires as instructed and it did register below 1 ohm.

 

What is the next step? Do you think the new resistor I bought was defective? How would I check this properly?

 

I will gladly add more $ to to compensate for your time

Expert:  Ford snr master replied 7 years ago.
unfortunately there is no real good way to test the resistor since it has a thermal limiter inside of it that acts like a diode. i would believe you might have a bad resistor if the reading was less than 1 ohm, i would suggest replacing the resistor , possibly you could exchange it and tell them the old one is faulty so you won't have to pay again,.. and recheck the operation. The blower is ok, we know that, the switch is good, the wiring from the fan to the resistor is good, and the wiring from the resistor to the blower is good. That just leaves the resistor by process of elimination