heat/ac blower not working
 

i have a 96 tt 300z auto, at first the ac/heat blower would work then slowly but surely it wouldnt. i bought a relay but cannot figure out where it goes? i hear a faint clicking noise around the kick panel fuse area when i try to engage the heat/ac but no blower. im freezing wondering if anyone can help, only time i have heat is at high speeds!