14
IX. Troubleshooting
Problem
Solution
Horn does not activate when I turn off accessory
power and open the front door, but I can hear a
relay inside the SCC module clicking on and off.
Check the connection on the horn relay wire. Verify that you have
made a secure connection.
Horn does not activate when I turn off
accessory power and open the
front door, and I do not hear any relays
clicking inside the SCC module.
Horn activates immediately when the
ignition/accessory switch is turned off.
If the front door switch is ac12V/+24V at the output, the door switch
wire should read “0” Volts
when the door is closed, and +12V or +24V when
the door is open, then P7 on the SCC should be used. If the front door switch
is grounds the switch output, the door switch wire should read +5 to
+12V/+24V
when the door is closed, and “0” Volts when the doo
r is open. In
this case the door switch wire should be connected to P8.
(1.)
Sometimes another device is connected to the same door switch and it
“grounds” the SCC door input through “
leakage
”
when the power is off to the
device (sometimes the flasher unit will cause this). In this case the SCC door
input must be isolated from the other device(s), or a separate door switch or
contact must be used for the SCC. A diode has been provided on the SCC
that may provide isolation from the other device. (See Fig. 6)
After the grounding door switch is directly connected to the SCC, connect the
other device (flasher) to P9. Retest the operation of each device, as the
device attached to P9 will not go completely to 0V when the door switch is
grounded.
(2.)
Door Switch is wired in conjunction with dome lights and a (new) dooro
jamb Switch is required to activate SCC-AM properly
(3.)
Check that door is not open or ajar causing the system to go to
into warning mode
Horn does not activate when I turn off accessory
power and open the front door, and I do not
hear any relays clicking inside the SCC module.
Check that the monitor has been ARMED. The yellow LED should be
illuminated. If not illuminated, check ARM input (P6) “Warn LTS” that
must receive a Bat + logic high after the ignition input is on.
TO RESET SWITCH at Rear of Bus
GND
FRONT DOOR
SWITCH
TO FLASHER UNIT DOOR INPUT
RECONNECT TO FLASHER DOOR INPUT
DETACH AND INSULATE WIRE
FIGURE 6
