1997/03/01 Caterpillar

Diode Removed From Junction Box Group{1400,1417}

Usage:

G3304 (37Y),
G3306 (07Y),
G3406 (4FD),
G3408 (6NB),
G3412 (7DB) Engines

A diode has been removed from between terminals 33 and 34 in the 4P-5469 Junction Box Group. On engines with an electric governor, these terminals are connected to the positive and negative terminals of the actuator, and to the governor control. When used in combination with a 1724 Woodward Governor, the former diode may have resulted in increased engine instability.

The diode can be removed from between terminals 33 and 34 in the 4P-5469 Junction Box Group in any of the above engines. The wiring diagram in the illustration shows the location of the diode (D1) to be removed. This diode is not needed and may help reduce instability if the engine is equipped with a 1724 Woodward Governor.

Wiring diagram for 4P-5469 Junction Box. Arrow points toward Diode D1 that can be removed.

Caterpillar Information System:

1997/03/01 New O-Ring Seal Used In Hydraulically Actuated Electronic Unit Injector (HEUI) Pump Group{1714}

1997/03/01 New Turbocharger Group And Air Cleaner Mounting Group Provide Improved Reliability{1051,1052}

1997/02/17 New Spark Plug Provides Better Heat Resistance {1555}

1997/02/17 New Relay Modules Replace Relay Assembly In Junction Box Groups {1400,1408}

1997/02/17 Improved Tube Assemblies And Electronic Control Group (Pressure Module) Improves Reliability {1058,1285}

1997/02/17 New Rod Ends Used In Exhaust Bypass Groups {1057,1250}

1997/02/17 New Harness Assembly For 3500B Engines {1408}

1997/02/17 Installation Of Piston Pin Retainer {1215}

1997/02/17 Premachined Valve Seat Inserts And Precision Valve Guide Increase Valve Life {1103,1104}

1997/02/17 New Exhaust Manifold Sections Contain A Port To Install Temperature Sensors {1059,1921}

1997/02/17 Basic Electronic Control Group (3408 Hi Performance Marine-E Rating) Improvement {1920}

1997/02/17 New Auxiliary Oil Filter Groups Reduce The Amount Of Air Accumulating In The Auxiliary Oil Filter Tank {1318}

1997/03/01 Caterpillar Part Numbers Are Used For XQ Rental, Generator Set Circuit Breakers{4461}

1997/03/01 Product Support Literature Available{0374,1000}

1997/03/01 Marine Transmission Oil Pressure Sensor Location{3323}

1997/03/01 4C-8180 Timing Tool Group Required For Checking And Adjusting Fuel Injection Timing On 3408C And 3412C High Performance Marine Engines{1250}

1997/03/01 Improved Bushing O-Ring Seal Available For Injection Pump Groups{1251}

1997/03/01 Improvements Made To Remanufactured 0R-3008 Fuel Transfer Pump{1256}

1997/03/01 The Components Of The 7C-5001, 100-8227, And 104-6775 Gas Pressure Regulator Groups Are Available For Parts Service{1270}

1997/03/01 New Terminal-Mounted Resistor Assembly Allows Proper Loading Of Digital Diagnostic Tool Data Line{1417}

1997/03/01 New "E" Rating Of 1350 Horsepower Available For 3412C High Performance Marine Engine{1902}

1997/03/01 New Gasket Used In Turbocharger Groups{1052,1061}

1997/03/01 New Adapters In Turbocharger Groups Provide Improved Sealing Between The Turbocharger And Exhaust Elbow{1061,1065}

1997/03/01 New Gasket Used In Aftercooler Groups{1063}