Ford Explorer Ambient Air Temperature Sensor Guide (1991-2001)
Is your Explorer's A/C acting up or the outside temperature display wrong? This sensor is the likely cause.
- A faulty sensor is a common cause for the A/C not working correctly in automatic mode.
- Replacement is very easy and a great DIY task for any skill level, often taking less than 30 minutes.
- For this part, a reputable aftermarket brand like Dorman or Standard Ignition offers the best balance of quality and price.
- The sensor is located behind the front grille, usually on the driver's side, making it easy to access.
Is Your Explorer's Outside Temperature Reading Wrong?
If the temperature display on your 1991-2001 Ford Explorer's overhead console is stuck, reads an impossibly high or low number, or doesn't change, a bad ambient air temperature sensor is the most common reason. This is more than just an annoyance; it can directly impact your comfort, especially in summer.
Symptoms of a Failing Sensor
A bad ambient air temperature sensor on this generation of Explorer has a few clear signs:
- Incorrect Temperature Display: The reading on your overhead console is obviously wrong, such as showing 35°F on a hot day.
- Automatic A/C Not Working: This is a major symptom. If the sensor incorrectly tells the climate control system that it's cold outside, the A/C compressor may not turn on, leaving you with warm air from the vents.
- Check Engine Light: In some cases, a failed sensor can trigger a Check Engine Light. You may find trouble codes like P0071, P0072, or P0073 when you scan the vehicle.
A Common Point of Failure
Located at the front of the vehicle, this sensor is exposed to rain, road salt, and debris. Over time, the sensor element can fail or the electrical connector can corrode, leading to faulty readings. Physical damage from minor front-end impacts is also common.
Choosing the Right Aftermarket Sensor
For a simple part like this, a quality aftermarket sensor offers the best value. The original Ford part is often expensive, and the technology is not complex. Here’s a breakdown of the brands available:
- Standard & Premium Aftermarket (Dorman, Standard Ignition, Holstein): These are well-known brands that produce reliable replacement parts. Dorman and Standard Motor Products (SMP) are trusted names in the industry and offer a direct fit and function that is comparable to the original. Holstein is also marketed as a quality alternative. For daily drivers, these brands provide a dependable, long-lasting fix without the high cost of an OEM part.
- Economy (Skyward, True Tech): These are typically budget-friendly options. While they will work, their long-term durability and the quality of their internal electronics may not match the standard aftermarket brands. If you are on a tight budget, they can get the job done, but a standard brand is recommended for peace of mind.
Pro Tip: Check the Connector
Before ordering, inspect the old sensor's electrical connector. If it's green with corrosion or the plastic is brittle and broken, you may need to replace the pigtail connector as well. Some aftermarket sensors come with a new pigtail for this reason.
Cost of Replacing the Ambient Air Temperature Sensor
This is an inexpensive and easy repair, especially if you do it yourself.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Sensor | $6 - $54 |
| New OEM (Ford) Sensor | $45 - $95 |
| Shop Labor | $60 - $120 |
| DIY Total | $6 - $54 |
| Shop Repair Total | $66 - $215 |
Frequently Asked Questions
Where is the ambient air temperature sensor located on a 1991-2001 Ford Explorer?
The sensor is located at the front of the vehicle, typically mounted to the radiator support brace behind the front grille. On most 1995-2001 models, it is on the driver's side. You can usually see it by looking through the grille with a flashlight.
Can I replace this sensor myself?
Yes, this is a very easy DIY job. It usually takes less than 30 minutes with basic tools. You typically don't need to remove the bumper. Access is through the grille or from underneath the front of the truck. The sensor is held in by a clip and has a simple electrical plug.
Will a bad ambient temp sensor stop my Explorer from starting?
No, a bad ambient air temperature sensor will not prevent your vehicle from starting or running. Its primary functions are for the temperature display and climate control system.
Is there a recall for this sensor on my Explorer?
No, there are no specific recalls or technical service bulletins (TSBs) from Ford for the ambient air temperature sensor on the 1991-2001 Ford Explorer.
Why does the aftermarket price vary so much?
The wide price range ($6.47 - $53.08) reflects differences in brand reputation, quality of materials, and whether the sensor includes a new wiring pigtail. Economy brands are cheaper, while premium brands like Dorman or SMP use higher-grade components and may offer a longer warranty, justifying a higher price.
Technical Specifications
OEM Part Numbers: F3VY-12A647-A F87Z-12A647-AA AU5Z-12A647-B
2-pin connector, push-in clip mounting style. Functions as a thermistor, where electrical resistance changes with temperature.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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