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.
No tools needed.
- 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):
on a similar vehicle (Lincoln MKZ):