There are TWO windings in the motor inside your compressor. Those two windings (the start winding and the run winding) will be in parallel. That is, one end of each winding will connect to the white wire.
When you take the start relay off the fridge compressor, you should see three terminals. Measure the resistance across each pair of terminals to get three readings. If there are no shorts in your motor's windings, two of those resistances should add up to the third.
Phone the electronics instructor at your local trade school. He'll have better test equipment that can accurately check your capacitor.