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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. Positive systems supply voltage to the interior
lights to turn them on, negative switched systems apply ground to illuminate the bulbs. To determine which
system you have you must locate the wires at the dome light. On a positive switched system, with all the doors
closed and thelights out, both wires atthe dome light will rest atground. When the light is activated,one of these
wires willswitch to+12 vdc. This is thevehicle's switchingwire. Ona negativeswitched system,with allthe doors
closed andthe lightsout, bothwires atthe dome lightwill restat +12vdc. When thelight is activated,one ofthese
wireswillswitch toground. Thisis theswitchingwire. For positive systems, connect the purple / 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 goodground. Positive systems are commonlyfound on Ford
vehicles. For negative systems, connect the purple / 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
constant12volt source. Negative systemsarecommonlyfoundonGeneral Motorsandimportvehicles.
Some vehicles which incorporate transistorized control of the dome light circuit, such as the 1999 Dodge
Caravan, may require that the purple / 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.
Note:
Positive Switched Dome Lighting
Red / black - Lamp on
To 12 pin
connector
on Monitor
To
constant
+12vdc
To
constant
+12vdc
Black / red - Lamp common
Purple / brown - Lamp Auto
Factory Door ajar
switch or Body
Control computer
