Whirlpool Refrigerator Compressor Start Relay & Overload Replacement — What This Part Does
The compressor start relay gives the compressor start winding a brief boost of power at startup, then drops out once the motor is running. The overload protector monitors current and temperature and opens the circuit if either gets too high, preventing compressor damage. Together they attach directly to the compressor terminals at the back of the refrigerator.
The start relay can fail internally so it no longer closes or energizes the start winding. The overload protector can stick open or trip repeatedly even when conditions are normal. Heat, age, and voltage spikes all contribute to failure. When either component goes bad, the compressor receives power but won’t start correctly or shuts off immediately on overload. Replacing the relay and overload assembly is straightforward and much cheaper than replacing the compressor.
Signs It Needs Replacing
- Compressor hums but won’t start You hear a steady hum from the back of the fridge but the compressor never kicks in and the cabinet stays warm.
- Repeated clicking every few minutes The compressor tries to start, clicks off on overload, cools down, and tries again in a cycle.
- No cooling and no compressor sound The lights and controls work but you hear no compressor noise at all and the fridge warms up.
- Burn marks or melted plastic on the relay You remove the rear panel and see visible scorching, cracking, or melted connectors on the start device.
- Compressor runs briefly then shuts off The motor starts for a second or two, then the overload trips and power cuts out before the cabinet cools.
- Relay tests open or very high resistance With a multimeter you measure infinite resistance across the PTC relay terminals when it should read 3 to 12 ohms at room temperature.
How to Replace It
- Unplug the refrigerator and pull it away from the wall so you can access the rear panel.
- Remove the screws securing the lower rear access panel and lift it off to expose the compressor and start device assembly.
- Photograph or label the wire connections on the old relay and overload assembly so you know which terminal is start, run, and common.
- Pull the relay and overload housing straight off the compressor terminal pins and disconnect any loose wire leads if present.
- Test the old PTC relay with a multimeter set to ohms; a good relay reads 3 to 12 ohms between the relay terminals at room temperature, and the overload should show 0 to 1 ohm continuity when cold.
- If the relay or overload is open or burned, slide the new relay and overload assembly onto the compressor terminals in the same orientation, matching the terminal layout and any keyed tabs.
- Reconnect any separate wiring to the new assembly following your photo or the wiring diagram printed on the compressor or in the kit instructions.
- Reinstall the rear access panel, push the refrigerator back into place, and plug it in.
- Listen for the compressor to start smoothly within a few seconds; if it still hums or clicks off, recheck your wiring and suspect a failed compressor rather than the relay.
The Part You Need
| Part | Notes |
|---|---|
| Whirlpool refrigerator compressor start relay and overload assembly | Amazon | Match your model and serial number from the rating plate inside the fresh-food compartment. Common OEM part numbers include 8201786, WP4387938, 4387938, 8201799, and 4387535. Some kits also include a start capacitor if your compressor design requires one. Verify terminal layout and wiring before installation, especially if your original part is discontinued and you are using a compatible replacement kit. |
Related Error Codes
If this part is failing you may also see one of these codes:
- Whirlpool Refrigerator Df error code
- Whirlpool Refrigerator E0 error code
- Whirlpool Refrigerator E1 error code
- Whirlpool Refrigerator E2 error code
- Whirlpool Refrigerator E3 error code
- Whirlpool Refrigerator E4 error code
- Whirlpool Refrigerator E5 error code
- Whirlpool Refrigerator E6 error code
- Whirlpool Refrigerator E9 error code
- Whirlpool Refrigerator Po error code
When to Call a Pro
If the new relay and overload assembly does not fix the problem and the compressor still hums, clicks, or won’t start, the compressor itself may have failed internally or the problem may lie upstream in the control board or wiring. Compressor replacement or refrigerant system work requires EPA refrigerant certification and specialized tools. Call a refrigeration tech to diagnose compressor health with a capacitor-start-run tester or amp clamp before spending more on parts.