User`s guide
CONNECTING THE DOME LIGHTS
The dome lights
in
the video monitor require three connections to the vehicle's wiring. There are two common
types
of
dome light circuits used, positive
or
negative switched system. Positive switched systems supply
voltage to the interior lights to turn on, negative switched systems apply ground to illuminate the bulbs.
To
determine which system you have to locate the wires at the dome light:
On a positive switched system, with all the doors closed and the lights out, both wires at the dome light will
rest at ground. When the light is activated, one
of
these wires will switch to +12 vdc. This is the vehicle's
switching wire.
On a negative switched system, with all the doors closed and the lights out, both wires at the dome light will
rest at + 12vdc. When the light is activated, one
of
these wires will switch to ground. This is the vehicle's
switching wire.
For positive systems, connect the violet / brown (Lamp auto) wire to the vehicle's switched wire. Then
connect the red / black (lamp on) wire to a fused constant 12 volt source and the black / red (lamp common)
wire to a good ground. Positive systems are commonly found
on
Ford vehicles.
For negative systems, connect the violet / brown (Lamp auto) wire to the vehicle's switched wire. Then
connect the red / black (lamp on) wire to a good ground and the black / red (lamp common) wire to fused
constant 12 volt source. Negative systems are commonly found on General Motors and import vehicles.
Note: Some vehicles which incorporate transistorized control
of
the dome light circuit, such as the 1999
Dodge Caravan, may require that the violet / brown (Lamp auto) wire be connected to the door pin switch
wire, as the additional current draw
of
the monitor's lights may not
be
supported by the output
of
the vehicles
body control computer.
Positive Switched Dome Lighting
To
12
pin
connector
on
Monitor
Red / black - Lamp on
Black / red - Lamp common
Purple / brown - Lamp Auto
To
constant
+12vdc
Fused
-----,
----
Factory Door ajar
switch
or
Body
Control computer
To
constant
+12vdc
,------
I Factory Dome light circuit
r------,
I
I
I
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I
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