If it were that easy I would have done this, try to look for a 1984 Eldorado Biarritz convertible top relay. I was on Rock Auto and 5 other sites just like it. The 84 Eldo Biarritz was NOT a factory convertible which is why the relay is not listed, heck I tried to look for the relays that fit an 82' to 86' Buick Riviera which WERE GM factory convertibles and could not find those ( figuring that the relay was the same)
So if anyone knows where I can get this please reply as this is absurd. I only find relays for the 71 to 76 Eldorados but nothing for 84' 85'