rarely happens in the summertime, in fall mostly when nights get below 50 and dew forms in the early am. i realized it was better to handle in my own when i took the starter out to have it bench tested and the fella at O'Reilly connected the cables to the motor instead of the relay and said he...
nope, clean cables and did I mention going on 3rd year. I physically inspected my starter. I know that the starter relay contacts are the culprit because I looked.
a few years back I noticed this same problem. i examined my starter and found the relay/solenoid contacts are just worn. its basically a copper washer attached to the solenoid actuator. if i key to start a few times it usually kicks over. I'll rebuild with new contacts when that stops working...