Problem with the Yellow Jacket relays is that the solder connections on the back of the relay can touch the contacts in the wire contact relay base. This can short circuits together not meant to be. I personally have been involved in trouble shooting three such occurances, twice while at Dover and once after leaving. All were documented, the first two bothto Dover and to World and the third to Works and Otis. No once seemed concerned. Best replacement is a new relay from Vertex and they aren't expensive.