1989/03/27 Caterpillar

How To Troubleshoot A Short-To-Ground In Power Wiring{1400}

Usage:

Reference: Understanding Causes Of Blown Fuses And Tripped Circuit Breakers and Understanding "Shorts," "Opens" and "Intermittents in this issue.

Shorts-to-ground, either continuous or intermittent, may be difficult to locate especially when they blow fuses or trips breakers. The following procedure may be helpful to locate a short-to-ground that blows fuses or trips breakers.

1. Disconnect one wire from the applicable circuit breaker or remove the fuse.

2. Temporarily connect a 9W1280 (24V) Lamp (or any 35 to 90 watt lamp) across (parallel to) the fuse holder or circuit breaker.

NOTE: Be sure temporary connections are reliable and will not cause shorts (unwanted connections).

3. If the short is present, this lamp will be "on."

4. To find the actual location of the short, disconnect, move, push/pull, and/or disturb the wiring and components in the effected circuit until the light blinks "on or off" according to physical motion.

Caterpillar Information System:

1989/03/27 Understanding Causes Of Blown Fuses And Tripped Circuit Breakers{1400,1420}

1989/03/27 Understanding "Shorts," "Opens" and "Intermittents"{1400}

1989/03/27 Limitations On Engine Cranking Time{1453,1401}

1989/03/20 Correct Torque For Bolts That Fasten Pulley To Stub Shaft In Radiator Group{1350}

1989/03/20 Improved Magnet Used In Rack Assembly{1705,1286}

1989/03/20 Elbow Fitting Available To Allow "Quick-Drain" Line To Oil Pan{1302,1307}

1989/03/06 New Bleed Screw Used On 7000 Series Fuel Injection Nozzles{1254}

1989/03/06 New Engine Wall Charts Give Maintenance Management Recommendations{0374,0375,7500,7557,7580}

1989/03/06 High Horsepower Standby Generator Set Engines{1000}

1989/02/27 Troubleshooting 3406B (PEEC) Truck Engines Equipped With Power Demand Cruise Control (PDCC){1705}

1989/02/27 Updated 7X1830 SPM For 8T5282 3406B PEEC DDT Available{1707,1705}

1989/02/27 New Features And Enhanced Fault Codes Available In New PEEC Personality Modules{1707,1705}

1989/03/27 Preventive Maintenance For Batteries{1401}

1989/03/27 Bolts Must Be Reinstalled In Same Holes In Companion Flange And Gear Output Flange{3305,3360}

1989/03/27 Exciter Rotor Retaining Bolt Torque Specification{4457}

1989/03/27 Additional Remanufactured Parts Available{1000}

1989/04/03 Follow Recommended Procedure When Adding Oil To Track Rollers And Idlers{4154,4159,4180}

1989/04/03 New Cylinder Blocks, Main Bearing Caps, And Main Bearing Cap Bolts Used{1201}

1989/04/03 Be Sure Electrical Components Are Correctly Grounded{1408}

1989/04/10 New Service Tools Available {0600}

1989/04/17 Recommended Wiring For Vehicle Speed Circuit{1705}

1989/04/17 Low Gear Limits May Be Ignored On 3406B (PEEC) Truck Engines{1705,1707}

1989/04/17 Orifice Plates Can Reduce Foaming In Expansion Tank{1354,1395}

1989/04/17 Correct Installation Procedure For Cylinder Head Studs{1100,1201}