Dig all that old potting compound out of the bottom of the relay board. Clean all connections top and bottom and refill/replace the potting compound to reseal bottom of relay board from the elements. . Several manufacturers make it. The round relays are interchangable, There is usually an extra spot on the relay board for unused accessories to keep a spare. If one ever fails on the road, just swap out as necessary. Front headlights have same relay.
