I had the same problem on my 88. The relay was full of water. I made sure I mounted it right side up instead of upside down. My leak from from a grommet that was pulled loose from the fire wall.

My issues were low power and intermittent stalling.

Never had a problem since I uprighted the relay.

Hawk

The water is most likely coming in around the wiper motor hole. I have that merit badge and also burned up an almost new relay thanks to that leak. My fuel pump was running with the car just sitting out in the drive however. After drying it out, it was dead.

Check the drains at the bottom of the car where the vents in the center of the car route the water. If those are clogged that will cause water to back up and come out that wiper motor hole. You can pull the carpet back and pull out the large round plastic plug and get a vacuum hose up in there. Be ready for a lot of junk and gunk if not done recently. And check your floorpan, that is also a well known rust out source, the water runs to the rear seat pan and let the rust begin.

Slip a plastic bag like a zip lock and put a zip tie to hold it in place and keep the new relay dry until you get the leak sorted out.

Jumper on the fuses will not do any damage as long as your jumpers are not having issues.

Good Luck,

Paul

PS: I now have a known good relay in the back of the car ready to go just in case.