Operating Light Control Rheostat Does Not Change Light Brightness

METER: METER / GAUGE SYSTEM: Operating Light Control Rheostat does not Change Light Brightness

Operating Light Control Rheostat does not Change Light Brightness

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. SYSTEM CHECK
Result:

B -- INSPECT LIGHT CONTROL RHEOSTAT
A -- Continue to next step.
2. INSPECT LIGHT CONTROL RHEOSTAT (TAIL, GND)

(a) Disconnect the R7 connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NG -- REPLACE LIGHT CONTROL RHEOSTAT
OK -- Continue to next step.
3. INSPECT LIGHT CONTROL RHEOSTAT (TAIL, TAIL CANCEL)

(a) Check signal waveform.
(1) Remove the light control rheostat with connectors still connected.
(2) Check the signal waveform according to the condition(s) in the table below.
OK:

HINT: Duty ratio changes as illumination becomes darker ("A" becomes longer).

(b) Disconnect R7 connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (LIGHT CONTROL RHEOSTAT - COMBINATION METER)

(a) Disconnect the C9, C16 and R7 connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE COMBINATION METER ASSEMBLY
5. INSPECT LIGHT CONTROL RHEOSTAT

(a) Disconnect the R7 connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPLACE LIGHT CONTROL RHEOSTAT
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (LIGHT CONTROL RHEOSTAT - COMBINATION METER)

(a) Disconnect the C16 and R7 connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE COMBINATION METER ASSEMBLY