Hi - horn not working.

I pulled the horn off and tested on a battery and the horn works. Checked fuse 15 - horn and wipes - fuse good and wipers working.

I cut back the wires a bit on the horn connectors under the car to make sure I had good clean wire contact to horn - but still the horn no work.

Thinking it might be steering wheel switch... or a break in the circuit. I can see the wires to the horn join in another loom of wires and seem to go straight into the firewall. Does not seem to be another connector along the way.

The wires under the car close to the horn are in fair shape but it is possible there is a break in the last section of wiring. I could cut that back a few feet into good wire.

There are two pairs of wires that run to the horn - where do they split from - they both seem to go all the way back. I tried each pair and neither pass current.

Does anyone have any thoughts or maybe suggests some predictable horn circuit failure I can look at?

Thank you,

Dean