1975 seatbelt light

[Rangerdale]

Hello, new to the forum, I have a 1975 thunderbird, build date of 6/75.
My problem is the seatbelt light won't go off, the buzzer stops when I pull out the belt from the retractor, but light stays on.
Is there a relay or timer I need to replace, if so, where is it located, what does it look like?
Thanks!

 

[Bird 71]

Check the plug inside both front retractor covers, if ok I would check the seat belt interlock relay on the rt front inner fenderwell.