Horn not working

[swimmermjs]

My horn has ceased working! When the steering wheel push button is pressed the horn makes a quiet "squeak" and nothing else. I have taken the horn off the vehicle and directly connected it to the battery and it works - very loud. I have taken the steering wheel and checked / cleaned the terminals and connecting ring and re-fitted everything. The terminals and plugs look OK. Does anyone have any similar experiences as the next step is trying to trace the wires down the column.
Thanks

[Reimotim]

Think there is a cablethat is at the bottom of the steering column that can sometimes become worn. Worth a look.
What voltage are you getting at the termials?