64 Reference
GROUND SWITCHING CONVERTERS
DWG NO. 4046
GROUND SWITCHING CONVERTER
A dual beam headlight has three connections,
high beam, low beam, and common. In a ground
common headlight system the common is con-
nected to ground and the dimmer switch con-
nects 12 volts to either the low or high beam
connection.
Prior to 1999, a ground common headlight sys-
tem was used on all models of Chevy, Ford, and
Dodge trucks. Hiniker plows were also manu-
factured using a ground common system. Re-
lays were used to switch the 12 volt high and
low beam signals from the dimmer switch over to
the plow high and low beams. The common con-
nection of the plow headlight assemblies was
made through the mounting bolt attached to the
grounded plow frame.
In 1999, Chevy and Dodge came out with some
models that used a 12 volt common system. In-
stead of the common being connected to ground
and the dimmer switch connecting 12 volts to
either the low or high beam connection, the re-
verse is true. In a 12 volt common system the
common is connected to 12 volts and the dim-
mer switch connects ground to either the low or
high beam connection.
These models did not send the 12 volt high and
low beam signal needed by the plow. To solve
the problem, the Ground Switching Converter
was created.
Using the low beams as an example, the Ground
Switching Converter provides 12 volts to the
plow low beam connections when it receives
ground on the truck low beam line. Refer to
DWG. NO. 4047 for the following. The common
(12 V) is connected to one side of the low beam
relay coil (85) and relay switch (30). When the
truck low beams are turned on, the low beam
signal (GND) goes to the other side of the re-
lay coil (86) and turns on the relay. The common
(12 V) is switched to the low beam output (87)
and goes to the plow as the 12 volt low beam sig-
nal. The action is the same for the high beams.
