Quick Fix (workaround) Ford Fusion AC Evap. Sensor

173,997

13

116

Posted

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):

Share

Recommendations

  • Microcontroller Contest

    Microcontroller Contest
  • Spotless Contest

    Spotless Contest
  • Science of Cooking

    Science of Cooking
user

We have a be nice policy.
Please be positive and constructive.

Tips

2 Questions

0

Great idea, I bought a pack of resistors, pulled the glove box but have no wire in the third from left top hole, I think it is actually #14. 2011 ford fusion. Which 2 wires should I use? Side note, after plugging the wires back in to try gain another day the AC chilled very good until I turned it off and back on. Attached is 2 pics of my wire cluster. Thanks for your help!

Screenshot_2018-04-18-21-32-07.pngScreenshot_2018-04-18-21-32-00.png

tried to.bypass evap sensor but when I removed glove box band pulled plug in instructions it say to tie into #3 and #4 wire but there is no #3wire on my fusion

107 Comments

Worked like a charm. I have 2011 fusion 4 cyl SE. My wire harness was blue and pins 13 and 15 worked. Also I couldn't find a 37 kohm resistor so I used a 36 1/4 watt. No issues. Thanks so much for this instructable. Saved me paying $1000 to Ford. Entire job including soldering iron cost me only $25.

Kudos to You Craig! I'm very happy to know that the instructions were useful. If you have any photos, please send-me, I will update the info a give you the credits.
Regards.
Erwin.

Could you help me with verifying why colors my wiring would be? I have a 2011 Ford Fusion SEL, would it be the same as yours? Do you have any pics? I would like to try this on mine

Hey, did you ever get this figured out? Looks like my 13 is black and purple and 15 is grey and blue.

Hey Bryan! I was able to get it, sadly I don't remember what the cookies were. The fix worked great for almost a year and then I traded the car for a new Nissan Altima. It was super simple after finding this post, I just wish I'd have came across it about a year earlier! Thanks again!

Could you help me with verifying why colors my wiring would be? I have a 2011 Ford Fusion SEL, would it be the same as yours? Do you have any pics? I would like to try this on mine

My 2011 fusion does not have a wire in 3rd slot do i just go by color?

1457545535275-1885970960.jpg

Hey, did you ever get this figured out? Looks like my 13 is black and purple and 15 is grey and blue.

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..