You're right it may be the relay or starter. This is what happens: I
hear the relay click, the compressor does not start. After 10 secs, the
relay clicks off, presumably its getting hot trying. After a minute,
same thing, over and over again. If I knock the compressor (which may
jiggle the relay I guess), the thing sometimes starts. At that point I
let it go as long as it can until my groceries are cold, and try not to
open it too much!

Anyone think it could be the starter and relay? When the compressor
runs, its sounds smooth and quiet.

Thanks!

Dean