DIFFERENTIAL LOCK INDICATOR LIGHT WILL NOT LIGHT.

TM 5-2420-224-20-1

Table 3-5. Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

ELECTRICAL SYSTEM (CONT)

53. DIFFERENTIAL LOCK INDICATOR LIGHT WILL NOT LIGHT.

NOTE

Refer to wiring diagram for all wiring repair steps.

Step 1. Pull instrument cluster panel light (1) out of dashboard (2).

Step 2. Remove differential lock indicator lamp (3) and check for continuity.

If there is no continuity, replace lamp.

If there is continuity, go to step 3.

NOTE

Vehicle MASTER disconnect switch must be ON and master light switch set to

PANEL BRT. Failure to do so will cause erroneous results.

Perform steps 3 thru 5 with differential lock engaged.

Step 3. Check for +24 VDC between wire 372 (4) and ground at instrument cluster

panel light (1).

If +24 VDC is not present, repair wiring 372 between

instrument cluster panel light and fuse box 1.

If +24 VDC is present, go to step 4.

Step 4. Disconnect connector C (5) and check for +24 VDC between wire 221 (6)

and ground.

If +24 VDC is not present, repair wiring 221 between

connector C and instrument cluster panel light.

If +24 VDC is present, reconnect connector C and go to step 5.

Step 5. Set master light switch to OFF and connect jumper between wire 221 (6)

and wire 03 (7) at differential lock indicator switch (8). Set master light

switch to PANEL BRT and check if differential lock indicator light is lit.

If differential lock indicator light is lit, replace differential lock

indicator switch (page 4-207).

If differential lock indicator light is not lit, repair wiring 221

between differential lock indicator switch and connector C.