Amana Dryer Moisture Sensor Not Detecting Dry Clothes:... | appliancefaults.com

Technical Background:

The moisture sensor in an Amana dryer typically consists of two metal bars inside the drum. When clothes are wet, they create a conductive path between these bars. The dryer's main control unit (MCU) monitors the resistance between these bars. As the clothes dry, the resistance increases. Once the resistance reaches a pre-determined threshold, the MCU terminates the drying cycle. This circuit operates on low voltage, typically 5V DC supplied by the MCU.

Symptoms:

My Amana dryer runs and runs, but the clothes are still damp at the end of the cycle. It doesn't seem to be sensing that the clothes are dry. I have to manually set the timer to get them dry.

Possible Causes:

Defective moisture sensor bar(s).
Broken or loose wiring to the sensor.
Faulty control board (MCU) not reading the sensor signal.
Lint buildup insulating the sensor bars.
Damaged or worn sensor brush (if applicable model).
Grounding issues within the dryer chassis.

Solution:

1

Disconnect power to the dryer at the breaker panel. Verify zero voltage with a multimeter.
2

Locate the moisture sensor bars inside the dryer drum, usually near the lint filter housing.
3

Visually inspect the sensor bars for damage, corrosion, or excessive lint buildup. Clean with a soft cloth and isopropyl alcohol.
4

Using a multimeter, test the continuity of the sensor bars. An open circuit indicates a defective sensor. Replace if necessary. After cleaning, ensure conductivity between the bars with a damp cloth completing the circuit.
5

Check the wiring connections to the sensor bars and the control board. Look for loose connections or broken wires. Repair or replace as needed. Use a wire stripper/crimper for secure connections.
6

If the wiring and sensors appear good, the control board may be faulty. Check the voltage to the moisture sensor circuit from the MCU. Consult the wiring diagram for specific voltage values. If the voltage is incorrect or absent, the control board likely needs replacement. Note: Control board replacement often requires licensed technician service.
7

After repairs, reassemble the dryer, restore power, and test the dryer's auto-dry cycle.

Safety Warning:

Disconnect power to the dryer at the breaker before performing any repairs. Lock Out/Tag Out (LOTO) procedures should always be followed to prevent accidental energization. Dryer circuits operate at 240V AC; contact with live voltage can be fatal.

Prevention:

Regularly clean the lint filter after each use. Periodically (every 6 months) vacuum out the lint trap housing and inspect the moisture sensor bars for buildup. Use dryer sheets sparingly as they can leave a residue that affects sensor performance. Check the dryer vent for blockages annually.

Expert Tip:

Some Amana dryer models have a diagnostic mode. Consult the service manual for your specific model. Typically, you can access it by pressing a specific sequence of buttons on the control panel. This mode can display error codes related to the moisture sensor, providing more information for diagnosis.

Frequently Asked Questions

•How do I test the moisture sensor bars with a multimeter?

Set your multimeter to the ohms setting (resistance). Place one probe on each sensor bar. A reading of infinity (open circuit) indicates a defective sensor. After cleaning, lightly dampen a cloth with tap water, squeeze excess water out, and place the damp cloth across both bars. The multimeter should read approximately 1-10 ohms, indicating a closed circuit.

•Where can I find a wiring diagram for my Amana dryer model?

Wiring diagrams are often located inside the dryer cabinet, either attached to the back panel or near the control board. You can also search online using your dryer's model number and "wiring diagram." AppliancePartsPros.com and similar websites often have diagrams available.

•How much does a replacement moisture sensor cost?

Replacement moisture sensors typically range from $20 to $50, depending on the model and supplier. Check online appliance parts retailers like RepairClinic.com or Sears PartsDirect.

Amana Dryer Moisture Sensor Not Detecting Dry Clothes: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I test the moisture sensor bars with a multimeter?

•Where can I find a wiring diagram for my Amana dryer model?

•How much does a replacement moisture sensor cost?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: