OK, if the relay is clicking then check the contact side of the relay. Check the 20A DEF fuse first and make sure it's OK. With the rear defroster on you should have +12 volts at the light green wire at pin 4 and at the green/blue wire at pin 2. If NO +12 volts at pin 2 that means the relay did NOT pick and go back to my prior post and troubleshoot that.

1998 Sportage - Gone.
2004 Honda Civic Coupe.
2007 Suzuki Grand Vitara - She got it.