TACHOMETER SHOWS NO INDICATION.

TM 5-2420-224-20-1

Table 3-5. Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

ELECTRICAL SYSTEM (CONT)

39. TACHOMETER SHOWS NO INDICATION.

NOTE

If STE/ICE-R Cl Engine GO-NO GO Chain does not diagnose cause of problem,

return to this troubleshooting table.

Refer to wiring diagram (page 3-138) for all wiring repair steps.

Step 1. Perform STE/ICE-R Cl Engine GO-NO GO Chain test procedures in the DCA

diagnostic mode.

If malfunction is found, refer to List of Tasks (page iii) or

Alphabetical Index (page Index-1) and repair or replace

damaged or faulty components.

If malfunction is not found, go to step 2.

Step 2. Loosen two captive screws (1) and pull bracket (2) out enough to gain

access to area behind bracket.

Step 3. Remove two clamps (3) and pipe assembly (4).

NOTE

For steps 4 thru 6, engine must be running.

Step 4. Check for +24 VDC between wire 31S (5) and ground at tachometer (6).

If +24 VDC is present, go to step 6.

If +24 VDC is not present, go to step 5.

Step 5. Disconnect connector D (7) and check for +24 VDC between wire 31S (5)

and ground.

If +24 VDC is not present, repair wiring 31S between

connector D and alternator.

If +24 VDC is present, repair wiring 31S between tachometer

and connector D.

Step 6. Check for +24 VDC between wire 36 (8) and ground at tachometer (6).

If +24 VDC is present, replace tachometer (page 4-128).

If +24 VDC is not present, repair wiring 36 between tachometer

and fuse box 1.

3-137