[928uk] analogue clock wiring

[phil rick]

looking online, such as Rogers site:

https://928srus.com/products/928-641-701-05-70b928-641-701-05-70b-analog-clock
it shows the usual 12v , earth and clock illumination and a not used
terminal.
just removed the one from this 90 and the factory wiring loom connector has
a wire in the not used location
before i break out the wiring diagram's anybody know what this wire does to
the clock?
cheers
Phil