Shed some light on the mystery plug

Could someone please enlighten me as to what the plug handing down on the right of the horn is for??

A PO has rewired the horn so it may be that????

 

Look like the plug for the brake pressure switch on the master cylinder

 

So it does.

 

Is that in the area shown?? not on the wheel? there is not much cable spare ???

 

Yep.

 

Thankyou guys much appreciated

 

I'm not convinced your horn's in the "right" place...