38 horn gremlins

[36coupe]

My horn started to blow when I turn the wheel on the way home the other night.
Made it home and parked the car and idsconnected the battery. I didn't want to get woken up at 3am with the horn stuck on.
I hooked up the battery and moved the car to the shop. The horn started blowing none stop.
The question is where is the first place to look for a fault?
Would it be at the top or bottom of the steering column?

Thanks