RESISTANCE TEST -726280277

TM 9-2320-364-20-1

Allow engine to cool before performing trouble-shooting maintenance. If necessary use insulated pads

and gloves. Hot engine components will burn and cause injury to personnel.

Remove all jewelry such as rings, dog tags, bracelets, etc. If jewelry or tools contact positive electrical

circuits, a direct short may result. Damage to equipment, injury or death to personnel may occur.

Use jumperwire only between terminals indicated. Failure to comply may result in damage to DDEC

components or wiring.

DDEC ECM connector terminals are easily damaged. Use care when connecting and disconnecting

connectors.

RESISTANCE TEST

(1) Loosen screw and disconnect engine

harness connector from DDEC ECM.

(2) Read resistance between wires 120

and 452 at engine harness connector

terminals R2 and Y2.

(a) If 5 ohms or more are present,

remove jumperwire and repair

wires 120 and/or 452 (see

schematic Fig 2-2) or notify DS

Maintenance.

(b) If 5 ohms or less are present,

connect OTS harness connector

and go to Step 5 of this Fault.

VISUAL INSPECTION

(1) Check terminals at engine harness

connector (DDEC ECM and

harness side) for damage; bent,

corroded and unseated pins or

terminals.

(a) If harness connector is damaged,

repair connector (Para 7-101) and

perform Steps (2) through (4)

below.

(b) If DDEC ECM connector is

damaged, replace DDEC ECM

(Para 7-56).

connectors are OK, replace

DDEC ECM (Para 7-56).

(2) Connect engine harness connector

to DDEC ECM and tighten screw.

(3) Install engine access panel with

22 washers, lockwashers and screws.

(4) Close top engine access cover.