fuel pump relay frying

Alright guys, I'm trying to help another Riv owner with a problem I haven't come across before. It was blowing pump fuses and turned out to be the relay. Replaced it and all was good for about 300 miles. Problem has returned. I would like to help but I'm kind of stumped. Any and all thoughts would be appreciated.

Could have gotten a less than par relay. Also, there may be too much voltage going to it. Turn down radio, pull up the back seat and listen for clicking in the black panel. I did my relay twice then the fuel pump. Access panel in trunk for pump but not a quick clean job!

If you can get an ammeter in place of the relay I'd be curious how many amps the fuel pump is drawing. But try another relay first.