Regarding the car horns sounding during flooding: Some cars have a metal
ring within the steering column that connects to the horn button. This
ring turns with the steering wheel. Below and touching this ring is
a small, spring loaded contact, fixed to the non-turning portion of the
steering column. The horn button typically completes a ground circuit.
Because of the bearings etc. the conductive path from the contact through
the ring to the horn button and then to ground is not a very good one, so
the relay that is used needs only a very very tiny current to close
and actuate the horn. For the same reason, the small amount of
current that can flow from the contact to the next nearest ground when
it gets wet is also often enough to close the relay too. This is an
older way of wiring a car horn. More often today, cars use a "clock
spring" harness or cable assembly, which is a kind of wiring
harness that resembles its name, and allows a reliable connection for
the buttons and switches that are sometimes found mounted on the
steering wheel.




--
Often wrong, never in doubt.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org