Illumination Circuit

AUDIO AND VISUAL SYSTEM: Illumination Circuit

Illumination Circuit

DESCRIPTION

Power is supplied to the radio receiver panel illumination when the light control switch is in the TAIL or HEAD position.
The intensity of the radio receiver panel illumination can be adjusted by the light control rheostat.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. SYSTEM CHECK
(a) Turn the light control switch to the TAIL or HEAD position.
Check if other displays or indicators such as the A/C switch indicator come on.
OK:
Other displays or indicators come on.
NG -- GO TO LIGHTING SYSTEM
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (RH R/B - RADIO RECEIVER)





(a) Disconnect the radio receiver R16 connector.
(b) Measure the voltage according to the values in the table below.
Standard voltage:





*1: Separate Type Amplifier
*2: Built-in Type Amplifier
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - LIGHT CONTROL RHEOSTAT)





(a) Disconnect the radio receiver R16 or R17 connector and light control rheostat R8 connector.
(b) Measure the resistance according to the values in the table below. Standard:
Standard resistance:





*1: Separate Type Amplifier
*2: Built-in Type Amplifier
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. INSPECT LIGHT CONTROL RHEOSTAT





(a) Reconnect the light control rheostat R8 connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NG -- REPLACE LIGHT CONTROL RHEOSTAT
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE