AT&T MMD85 - Manual (Page 8)

8
Installation Guide
Troubleshooting:
SYMPTOM:
No power at Video Monitor
Power but no video or
sound
Picture, but no sound
REMEDY:
-Verify +12 VDC on Red wire at 2 pin Power Harness behind video
monitor. Verify ground connection with continuity test from known
good ground to black wire at 2 pin Power Harness
-Verify that the correct source is selected (i.e.: 1 or 2). Verify that the
source is on and playing a known good media (such as a videotape).
Verify connections at both ends of the source component harness.
-Verify that the headphones are turned on; check headphone batter-
ies
-Verify that power is available to the FM Modulator; make sure modu-
lator is tuned to the correct FM station
Negative Switched Dome lighting
To 3 pin
connector
To
constant
To
constant
Factory Door ajar
switch or Body
Factory Dome light circuit
Red / black - Lamp on
Black / red - Lamp common
Violet / brown - Lamp Auto