You originally wired the live through the switch so it was switched live and you spured of pin 30 to the energised pin of the relay (85).

How it works in the second diagram 30 and 85 each have there own independant +12V feed. Since the relay is not grounded as it's wired through the switch the relay can not close hence no power to fans. When the switch closes this connects the earth from the relay to earth hence the relay trips. (Switched earth)

Martin