a backyard repair i do on gm coils with broken harness retainer clips for the underprivileged is to loop 2 wire ties under the coil and over the plug, then pull them tight to hold the plug into the coil. i overlap them so they are 90º off, making a "X' pattern on top of the plug.
you should be able to do the same thing on the compressor.

 

hmmm I can see, not sure I have enough room under the plug but will give it a go thanks