Quick Fix (workaround) Ford Fusion AC Evap. Sensor

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Introduction: Quick Fix (workaround) Ford Fusion AC Evap. Sensor

Workaround that avoids the replacement of the AC evaporator sensor from all Ford Fusions up to 2012. A problem that Ford should take care in guarantee considering the poor quality of the sensor used and because it is a recurring problem on several vehicles. Ford recommends the replacement of this sensor, to do that, the complete dashboard removal is mandatory. The service costs around U$ 600 and the sensor around U$ 20. Therefore, it is not cheap.

Tools:

No tools needed.

Material:

- 1 37kOhm resistor (1/8 W);

- Electric tape;

- Stanley Knife

Step 1: Glove Box Disassembly

Disassembly of the glove box pressing it on both sides.

Step 2: Attention to the Cord!

Step 3: Connectors

Pay attention to the left connector (it may be green or blue - normally green).

Step 4: Wiring Schematics

Wires BU-BN (blue/brown) and VT-BN (violet/brown) are the wires connected to the temperature sensor (thermistor). In some cases the thermistor will open (resistance=infinite) in others it will show the problem only when moisten, it will cause the AC compressor shut down. If this is your case, the wires must be chopped off in order to guarantee the good resistance measurement. Looking the backside of the connector blue or green (wire side), the pins will be the third and fourth from left to the right on the up row. (check here: https://www.youtube.com/watch?v=imnNjh6wGo4).

Step 5: Choice of the Good Resistor

Resistor X temperature

The good resistor is shown on the chart. A 37 kOhm resistor will generate a signal equivalent to 20 Celsius and avoid the compressor to shut down. When using AC on very cold days, the evaporator may ice, in this case you have only to shut the AC off and let the ventilation working.

Step 6: Resistor Assembly

The pictures show the resistor assembled.

Step 7: Sensor Replacement

There are three good youtube videos showing the dashboard disassembly.
Shortest service time video:

Longest service time video following Ford instructions (by the book):

Workaround
on a similar vehicle (Lincoln MKZ):

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  • 2010 Fusion Hybrid. ...-ErikC69

    ErikC69 made it!

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104 Comments

I have a 2011 fusion sel. I put a 32k ohm resistor on pins 13 and 15, no cold air still, but now air only blows through defroster vents, won't switch to front or foot vents. (Didn't do this before, before was just hot air, had same problem in last 06 fusion.) what should I do? I figure wiring back will return vent switch problem, but am I using a wrong wire? They are cut and soldered to the resistor not spliced in

Question. 2011 fusion so I used pin 13 and 15. Thought I could just cut the wires and put in a pigtail and new sensor, thought it would work like relocation sensor. Still doesn't work. Any suggestions? Before I changed scanner said original sensor was reading -266 degrees so I ashamed faulty..

Call ford this is ridiculous!! This should be a recall!! Please

Not a recall...the Fusion engineers just need to be flogged for not adding an access hole in the firewall, that's all.

does the wiring stay the same n u add the little ohm resister to it.or does the resister finish the electric connect

Did you get a response on this? i am having the same issue. Tried to splice and i didn't work, wondering about the resistor finishing the circuit

I just did this to my '08 Fusion. Add the resistor to the two wires, they DON'T need to be cut. Mine works beautifully but watch for reduced airflow coming from the a/c vent. As the instructions above say, that's a sign the evaporator is icing up. If that happens, turn off the a/c for a while 'till it thaws.

It will work only if the temperature sensor (resistor/thermistor) is completely open (resistance is equal to infinite). In my case the thermistor was sending a wrong reading. I replaced the part by a new one. If this is your case, you must cut the wires going to the sensor, it means that the resistance will be only of the resistor and not the sum of the resistor and the damaged thermistor. You can also check de possibility of replacing the original part by other (it costs US15 I think) and use the technique shown in the video https://www.youtube.com/watch?v=WqLWwIFTk_k
. You do not have to disassemble the whole dashboard. I did that.

It works.2006 6 cylinder fusion. Pin 15 blue/gray and 13 purple/brown. 39k resistor found in old cb radio. Spiced and solder directly to above wires. 2nd from left top and 4th top wires. They are numbered on the plug but hard to see. Top left(16) was empty by the way. Very easy. Just remember to cycle ac on and off once in a while as it won't disengage on its own like its supposed to if system gets to cold and starts to freeze up. Haven't tested fully yet to verify that but that's what I've read and it makes sense. All I know is that I have ac again now and the hack works. For now that's awesome. Nothing lost.

Congrats man! If you have any photos and would like to improve this instructable, please let me know. Best. Erwin.