What you're saying isn't making sense or you're not including enough detail. If there is a short when the relay is plugged in, then the fuse will blow. If the fuse isn't blowing, then there is no short.

BTW, is there a label or number next to that 30 amp fuse or any fuse that might be blowing?

 

The relay turns something on that causes a drain on the battery. Not enough of a short to blow the fuse, just a completed circut that shouldnt be there. What does that relay turn on?

 

btw that fuse is in the #3slot 30 amps

 

if we have you stumped let me know[:-]. we'll go to option two.....dynomite

 

While blowing something up with dynamite can be satisfying, I prefer to vent my frustrations with a large heavy machete. Keeps the neighbors in line.