since it clicks several times when it acts up the next time after the 1st click STOP & down at the starter itself jump the 2 terminals being careful not to touch the starter case. If the starter is good then go back up to the relay & clean all connections incl ground as double R suggested & last would be to R&R the relay as you mentioned. I would be inclined to think that the relay is bad IF all 6 ends of the big cables are clean.