El cables jaguar s type

I have a s type 2005 mod 2,7 diesel.

"When fault checking due to a not working horn i saw a red quick connector with three cabels hanging down in the drivers footwell (LHD) The cables has red, brown and green colure and the connector is black and red.
Anyone know what this are for and where it shall be connected "

Welcome Erik.
I have a 2000 V6 LHD and I looked under the dash and did not see anything like that. I saw a cable with red, yellow, green and black wires above the steering column.
Perhaps your mystery cable is for some feature that your car does not have.