BAR-BUS 1270527 - Caterpillar

D379, D398, D399, G379, G398, G399 Engines And 3400 Series Engines With EG3P Woodward Actuator AssembliesReports indicate that in some cases the polarity of the connector on the EG3P actuator may be reversed. See Illustration 1. If the wiring from the 2301 Governor has also been reversed, there will be no problem in running the engine. But if a new actuator with the correct polarity is installed, the engine will not start. This problem may occur with the following actuator part numbers:
7W1454, 7W1455, 7W6122, 7W6652 and 7W6653
When an EG3P Actuator Assembly is replaced and it will not function, reverse the polarity of the wires to the actuator. The most convenient location to reverse the polarity is at the terminal strip in the engine mounted junction box. See Illustration 2. Reverse the wires connected to terminals 33 and 34 in the junction box. This will insure that the polarity of the diode (if used) is not reversed.
Illustration 1. Woodward EG3P Actuator Assembly.
Illustration 2. Location of terminal strip in the engine mounted junction box.Special Instruction Form SEHS8629 has additional information about this subject.