I bought a replacement from a certain famous e-retailer but they sent me the wrong part. Damn. I tried again and was guaranteed overnight (8 AM!) delivery. 3 days later they cancelled the order as "undeliverable." Don't worry, they'll refund my money in a few weeks... At this point, my fridge had been broken for 5 days.
It was only at that point, That I went to AppliancePartsPros. Less than 24 hours later fridge was working great again with an actual Whirlpool part.
Who needs this part? Your fridge isn't cooling. You have a compatible fridge that clicks to turn on the compressor but don't hear the fan inside the compressor (not beside, inside). A few seconds later this part clicks again to turn off the compressor due to overheating. A minute or two later the whole thing repeats. If the capacitor (the black thing that plugs in) doesn't look deformed, then this part is probably preventing the capacitor from sending enough juice to start the fan in the compressor.