Express 1/2 Ton Van V8-305 5.0L VIN M SFI (1998)
Audible Warning Device: Component Tests and General Diagnostics
The Multi-Function Alarm Module is powered by HAZARD Fuse 5 at all times through the ORN (1040) wire. It is grounded through the BLK (150)
wire to Ground G201. It produces audible warning alarms when the driver's side safety belt is no fastened, when the Headlights or the Park Lights are left
on, and when the key is left in the Ignition Switch as the driver exits the vehicle.
Fasten Safety Belt Warning Alarm
The Safety Belt Lamp on the Instrument Cluster will light then flash after 15 seconds and the audible alarm will sound for five seconds if the
driver's side seat belt is not fastened when the Ignition Switch in placed in RUN or START. The light will automatically extinguish and the audible
alarm will be automatically silenced by fastening the seat belt. When the driver's side seat belt is fastened, contacts in the Seat Belt Switch close.
This provides a ground path to Ground G201 through the BLK/WHT (238) and BLK (150) wires. The Multi-Function Alarm Module then senses
that the seat belt is fastened. When the Ignition Switch is in RUN or START, voltage is sensed at the Multi-Function Alarm Module from
GAUGES Fuse 4 through the PNK (39) wire. If the seat belt is not fastened and the Ignition Switch is in the RUN or START position, the alarm
conditions are met. However, a timing circuit in the module inhibits the alarm after five seconds if the conditions remain present. If the seat belt is
opened after the five second delay, the alarm remains inhibited.
Key-in Warning Alarm
The Key-In Warning Alarm is presented if the key remains in the Ignition Switch and the driver's door is opened. This alarm remains present until
the key is removed or the door is shut. The Multi-Function Alarm Module senses that both the key is in the Ignition Switch and the door is open by
the ground path through the LT ORN (80) wire, through the Key-In Warning Switch in the Steering Column, through the TAN (159) wire, through
the LF Door Jamb Switch, and through the BLK (150) wire to ground. For Recreational Vehicles (Uplitter Provisions), the ground is G200 and
G201. For all other vehicles, the ground is G201. Any open in the ground path will inhibit the alarm.
Lamps-on Warning Alarm
The Lamps-On Warning Alarm is presented if the Headlights or the Park Lights remain on when the Ignition Switch is turned off. The alarm
remains present until the lights are turned off or the Ignition Switch is placed in the Run or Start position.
With the Headlamps or Parking Lamps on. voltage is sensed by the Multi-Function Alarm Module from PRK LPS Fuse 9 through the ORN (240)
wire, through the Headlamp Switch, through the IP Dimmer Switch, through the DK GRN (44) wire, through ILLUM Fuse 14, and through the
ORN (1040) wire. With the IP Dimmer Switch adjusted for very dim illumination, the voltage sensed at the Multi-Function Alarm Module may be
to small to set the logic and enable the alarm. Testing should be done with the IP Dimmer Switch adjusted for maximum illumination.
With the Ignition Switch in RUN or START, voltage is sensed by the Multi-Function Alarm Module from GAUGES Fuse 4 through the PNK (39)
wire. When this voltage is not present but voltage is present from the IP Dimmer Switch, then the alarm conditions are met.
