IMPORTANT: Please throw the breaker so there is NO POWER leading to the heat pump.

Using a DMM, check for continuity between the three compressor windings and the ground. While you are doing these tests, please make sure all connections are secure. 

1: Disconnect the power
2: Remove the side cover from the heat pump
3: Locate the compressor – remove the insulation cover top held down by velcro straps (see image “comp_insulation-cover.jpg”)
4: There is a black protective cover held down by a single nut. Remove the nut and then the cover (see image “comp_winding-cover.jpg”)
5: Check the continuity from each coil at the compressor to a ground point.  (see image “comp_windings.jpg”)
6: You can also test the resistance between each coil, which should be equal to each other.