Federal Signal Corporation PA300 Series 690009 Installation And Operating Instructions Manual page 12

4-5. TAP II FUNCTIONS.
Tap II allows the driver to change the siren
sound via the vehicle's horn ring. This feature is
especially effective for clearing traffic. The chart
below demonstrates how the horn ring can be used to
change the siren sound:
TAP II FUNCTIONS
Selector First Horn
Switch Ring Tap
Position Produces
Wail Yelp
Yelp Wail
4-6. PRESS AND HOLD FUNCTIONS.
Additional alternate sounds can be activated in
two other Selector switch positions, by depressing
and holding the horn ring for as long as the alternate
sound is desired. The chart below shows these
additional "Press and Hold" functions:
Selector
Switch
Position
Second Horn
Ring Tap Hi-Lo
Produces Manual
Wail
Yelp
-10-
PRESS AND HOLD FUNCTIONS
(Models 690009 and 690010)
Press on
Horn Ring
Produces
Air Horn
Peak and
Hold or
Air Horn
Release of
Horn Ring
Produces
Hi-Lo
Coast down
and silence
or silence