WP3977456 Dryer Push-to-Start Switch

Key Features

• Momentary Contact Logic: Engineered as a "push-to-start" safety mechanism that only sends a momentary electrical signal to the motor relay, preventing the dryer from auto-restarting after a power flicker or door opening.
• Heavy-Duty Internal Spring: Features a high-cycle tension spring designed to withstand thousands of presses without losing its "snap" or becoming stuck in the closed position.
• High-Arc Resistant Contacts: Manufactured with internal copper contacts treated to resist electrical pitting and arcing, ensuring a clean connection every time you begin a drying cycle.
• Standardized Spade Terminals: Equipped with two 1/4-inch male spade terminals for a secure, low-resistance connection to the dryer’s wiring harness, facilitating a true "plug-and-play" installation.

Replaces / Cross-Reference Part Numbers

• Primary Part Numbers: WP3977456, 3977456.
• Industry Standards: AP6009036, PS11742178, EAP11742178.
• Legacy Cross-Reference: 898073, 3395382, 3398095, 3399866, 3406684, 660991, PS352317.

Compatibility & Fitment

This start switch is one of the most common components used in Whirlpool-built dryers over the last 30 years. Key compatible brands include:

• Whirlpool & Kenmore: Fits hundreds of 29-inch wide residential dryers (e.g., Kenmore 70, 80, 90 series and Whirlpool Cabrio/Duet models).
• Maytag & Amana: Compatible with various Centennial and Bravos series units produced after the Whirlpool acquisition.
• Estate, Roper, & KitchenAid: Direct fit for value-tier and premium-tier models utilizing the standard console configuration.
• Crosley, Inglis, & Admiral: Fits various specialty and regional brands built on the Whirlpool chassis.
• Note: While this is a universal fit for many, verify the shape of the mounting "D-stem" on the back of your start knob to ensure a perfect match.

When to Replace

• Dryer Won't Start: The most common symptom; you press the button and nothing happens, even though the dryer is plugged in and the door is latched.
• Button is Stuck: The switch is stuck in the "In" position or feels "mushy," indicating the internal spring has failed.
• Intermittent Starting: You have to press the button multiple times or hold it down firmly for the dryer to finally engage the motor.
• Visible Burn Marks: Upon inspection, the plastic around the spade terminals is melted or discolored, signaling a high-resistance electrical failure.
• Continuity Failure: Testing with a multimeter shows no "continuity" (beep) between the two terminals when the button is manually depressed.

Installation Tips

• Safety First: CRITICAL: Always unplug the dryer or turn off the circuit breaker before beginning. You will be working directly with the 120V control circuit.
• Access the Console: On most models, you will need to remove a few screws from the back of the top console or pop the top clips to tilt the control panel forward.
• Wire Transfer: PRO TIP: Do not pull all wires at once. Disconnect one wire from the old switch and plug it into the corresponding terminal on the new WP3977456 to avoid a wiring mix-up.
• Tighten the Terminals: If the female connectors on your wiring harness feel loose, use a pair of needle-nose pliers to gently squeeze them for a tighter "friction fit" on the new switch terminals.
• The Door Switch Check: Before installing, verify your Door Switch is working. If the door switch is broken, a brand-new start switch will still not make the dryer run.