Volvo Repair: Horn wont toot, horn button, hot wire

Question
Hi, I just bought a used 240 wagon. It's a 93 and the horn isn't working. It's seems to get a low voltage 5-7 v at the connection. Any clues?
thanks.

Answer
I know that if you rap the horn...with a metal object....while someone holds the horn button....they may start working again...make sure connections are clean...clean ground....
       feed a hot wire to horn...directly from batt...
          this should be easy to figure out.

                Bilbo