Audiovox AVXMTG10U Instruction Manual page 13

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 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 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 switching wire.
For positive systems, connect the purple / brown (Lamp auto) wire to vehicle's switched
wire. Then connect the red / black (lamp on) wire to a fused constant 12 colt 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 purple / brown (Lamp auto) wire to the vehicle's
switched wire. The 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 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.
Positive Switched Dome Lighting
To 6 pin Red/black-Lamp on
connector
Black/red-Lamp common
on Monitor
Purple/brown-Lamp Auto
To
constant
+12vdc
Factory Door ajar
switch or Body
Control computer
To
constant
+12vdc
20
Negative Switched Dome Lighting
Red/black-Lamp on
To 6 pin
Black/red-Lamp common
connector
Purple/brown-Lamp Auto
Factory Door ajar
switch or Body
Control computer
To
constant
To
constant
21