Kitchen Large Electric Appliances - Whirlpool Fridge (ED25PEXHT02) Problem/Question?

I have had this side by side Fridge for not quite 4 years. Came home today to a mess, everything in the freezer had melted/thawed, and the fridge was very warm. I didn't hear anything running, so I unplugged it. The circuit checked out OK. I have pulled the piece of cardboard off the bottom back, and the compressor (?) was extremely hot? I let it sit for about an hour or so unplugged, then plugged it back in. The fan that cools the compressor came back on, and after about an hour or so of running, the freezer had started to blow out cool air. The question I have, is that it is making a random clicking noise up underneath somewhere, kinda like a relay or something. One time after a real loud click, I heard somewhat of a high pitched whine (wasn't real loud, just high pitched), which gradually stopped after about 10 or so seconds.
I know nothing about refrigerators :wall:
Does anyone have any ideas of what this could be, worth fixing or junking? Kinda disappointed in it has only lasted 4 years. Thanks in advance for any ideas / information!!

Rob

Just a little update.
This morning I decided to plug in the fridge, while watching the back of it. There is a little white plastic looking box on the side of the compressor.

When I plugged it in, the little box lit up like a christmas tree inside of it, then clicked, and it sounded like the compressor and everything cut on? This box has a white & red wire going to it, and according to the diagrams that I can find, it is a "OVERLOAD (SERVICE COMPRESSOR ONLY, INCLUDES RELAY)" & "START DEVICE, COMBINATION (START RELAY AND OVERLOAD FOR PRODUCTION COMPRESSOR ONLY)". I have a picture of the diagram at http://www.imopar.com/fridge.jpg
It looks like parts 12, 13 & 16. Any ideas? Thanks, Rob