I did a search and found this after I had the same thing a few weeks back. there are several threads about this.
also thanks for the belts they are in great condition, so much better than mine were.
If it is coming from the dashboard area it could be the following.....has something to do with the anti-theft device.
Clicking in 10AS Control Unit
AFFECTED VEHICLE RANGE:
DEFENDER (LD) VA992105 to VA999484
VA100300 to VA126471
INTERMITTENT CLICKING NOISE FROM DASHBOARD
An intermittent clicking noise may be heard coming from the dashboard on some '97 model year Defenders. The clicking noise sounds very similar to a turn signal flasher in frequency and loudness. Once the clicking noise begins, it will continue until the ignition switch is cycled off and then on again. The source of the clicking noise is a relay within the immobilization control unit (10AS unit). A revised unit is now available to address this symptom.
REPLACE IMMOBILIZATION UNIT
To address a customer complaint matching the above description, verify that the source of the clicking noise is the alarm ECU and replace the unit with the latest type.
AMR6430A Immobilization Unit