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 (ILL+, E)

(a) Disconnect the R8 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 (TC, LM)
(a) Check signal waveform.

(1) Remove the light control rheostat with connectors still connected.
(2) Connect the oscilloscope to the terminal C11-35 and body ground.

(3) 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) 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 C11 and R8 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 R8 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 C11 and R8 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