1998 GU TB45 radiator

Original plastic tank radiator was replaced by a local shop with a metal ADRAD several years ago. Whilst renewing a bottom radiator hose recently, I noticed that there is a sensor fitted to the driver’s side of the bottom radiator tank with a short wire and female connector going nowhere. Cannot find wiring with a male connector anywhere in the vicinity.
I suspect that this may have been a fitment for a different model. Have had no overheating issues or warning lights appearing, and A/C is working ok. Have Max Ellery’s manual, but this is of no help in this instance.
Can anyone help with an explanation? I am not sure what is going on here,
Many thanks bobmac1