Western Snowplows Midweight Series, Руководство механика

Страница: 33 / 104

Lit. No. 48163, Rev. 00 March 15, 2016
33
THEORY OF OPERATION
Blue Label Module (PN 29760-2)
NOTE: Limited vehicle application.
Certain model year 2014 and newer GMC and
Chevy trucks require this DRL module.
Refer to the online QuickMatch resource at
www.westernproducts.com for full details.
According to the vehicle manufacturer, all 2008
Ford Super Duty F-250/350/450/550 trucks
built before 04/18/2007 require this module.
Trucks built after that date and having the Plow
Prep Package use the green label DRL module
(PN 29070-1) described on the previous page.
Snowplow not attached to vehicle:
System is inactive. Vehicle lighting system
functions normally. Reason: No ground to module.
Snowplow attached to vehicle:
System is inactive until either the switched
accessory wire or the vehicle parking lights are
activated. Vehicle and snowplow lighting systems
function as outlined in the Theory of Operation
Overview. Reason: Ground path is established
from battery common to Pin C on Port A of the
3-port module via the following harnesses: vehicle
battery cable, vehicle control harness, adapter,
plug-in harness, vehicle lighting harness and
snowplow lighting harness.
• Activating a switched accessory wire (a
key-controlled power source) applies battery
voltage to the VACC input of the module,
which energizes the coil of the control power
relay (part of the 3-port module). Energizing
the coil of the control power relay causes the
relay contacts to shift from the "N.O." (normally
opened) position to the "N.C." (normally
closed) position, which supplies battery voltage
to the snowplow control via the plug-in harness
and the vehicle control harness.
• Activating the vehicle park light circuit applies
battery voltage to the module park circuit input.
The voltage is applied to a solid state power
device, which causes the device to turn ON
and apply battery voltage to the snowplow park
lamp filaments via the vehicle and snowplow
lighting harnesses. Voltage is also applied to
the module's high and low beam relay coils,
which causes the relay contacts to shift from
the "vehicle" to the "snowplow" position.
• With the four headlamp relays shifted to the
"snowplow" position, the vehicle high and
low beams are now directed to the snowplow
headlamps via the vehicle and snowplow
lighting harnesses. Toggling the dimmer switch
between high and low beam will toggle the
snowplow high and low beams.
• Activating the turn signal applies battery
voltage to the module turn signal circuit input.
The voltage is applied to a solid state power
device, which causes the device to turn ON
and apply battery voltage to the snowplow
turn signal lamp filaments via the vehicle and
snowplow lighting harnesses.
• On vehicles equipped with DRLs integrated into
the vehicle headlamps, activating a switched
accessory wire (a key-controlled power
source) applies battery voltage to the module's
high and low beam relay coils, which causes
the relay contacts to shift from the "vehicle"
to the "snowplow" position. This module will
transfer the vehicle DRLs to the snowplow.
3-PORT MODULE ELECTRICAL