Resistance Check of Communication Signal Harness of Diesel Generator

1. Serial cable

The data cable adapter requires the use of a serial cable when interacting with the computer. The use of test wires (part numbers 3822758 and 3822917) can prevent damage to the serial cable pins.

When measuring resistance, insert a test wire into the negative terminal contact 1 of the serial cable and connect it to the multimeter probe. Connect another test wire to the positive terminal contact 1 of the serial cable and connect it to the multimeter probe. When measuring resistance, the multimeter must display closed circuit (10 Ω or less). Repeat the resistance measurement steps for pins 2 to 9. The multimeter must display closed circuit (10 Ω or less) on each contact pin. If the circuit is not closed, the serial cable should be replaced.

2. Reference calibration harness

To avoid damaging the plug pins, use test wire part number 3823993 on the 8-pin plug, part number 3823994 on the 9-pin plug, and test wire part number 3824812 on the 3-pin plug.

Measure the resistance between each pin in the 8-pin connector and the corresponding position in the 9-pin and/or 3-pin plug, and the multimeter must display closed circuit (10 Ω or less). If the circuit is not closed, the reference calibration harness should be replaced.

3. Reference calibration cable

To avoid damage to the plug pins, a test wire (part number 382994) should be used on the 8-pin plug. Appropriate test wires are required to determine the ECM plug of the benchmark calibration cable.

Measure the resistance between each pin in the 8-pin plug and its corresponding position in the ECM plug, and the multimeter must display closed circuit (10 Ω or less). If the circuit is not closed, the reference calibration cable should be replaced.

4. 9-pin data communication cable and 9-pin plug

To avoid damaging the plug pins, use a positive test wire with part number 3823993 on a 9-pin Deutsch and a positive test wire with part number 3822758 on a 25-pin plug.

Measure the resistance between pins A, B, C, D, E, F, and G in the 9-pin plug and the corresponding positions in the 25-pin plug shown. The multimeter must display a closed circuit (10 Ω or less). If it is not a closed circuit, the data communication cable should be replaced.

5. 6-pin data communication cable and plug

To avoid damaging the plug pins, use a positive test wire with part number 3824811 on the 6-pin plug and part number 3822758 on the 25-pin plug.

Measure the resistance between pins A, B, C, and E in the 6-pin plug and the corresponding positions in the 25-pin plug shown. The multimeter must display a closed circuit (10 Ω or less). If the circuit is not closed, the data communication cable should be replaced.

6. 3-pin data communication cable

To avoid damaging the connector pins, a positive test wire (part number 3822758) should be used on the 25 pin plug; Use a positive test wire (part number 3823994) on a 3-pin plug; Use a positive test wire (part number 3822995) on the 2-pin power plug.

Measure the resistance between pins A, B, and C in the 3-pin plug and the corresponding position in the 25-pin plug shown. Measure the resistance between pins D and E in the 2-pin power plug and the corresponding position in the 5-pin plug shown. The multimeter must display a closed circuit (10 Ω or less). If the circuit is not closed, the data communication cable should be replaced.

7. Small backbone cables

To avoid damaging the plug pins, two positive test wires (part number 3823993) should be used on the 3-pin plug.

Measure the resistance between pin A on one end of the backbone cable and pin A on the other end of the backbone cable, and repeat the same step for pin B and pin C. The multimeter must display closed circuit (10 Ω or less). If it is not closed circuit, the backbone cable should be replaced. Measure the resistance between pin A and pin B at either end of the cable to measure the terminal resistance. The terminal resistance must be between 50 and 70 Ω.

8. Change cable

To avoid damaging the plug pins, two negative test wires (part number 3823994) should be used on the 3-pin plug.

Measure the resistance between pin A on one end of the transformation cable and pin A on the other end, and repeat the same step for pin B and pin C. The multimeter must display closed circuit (10 Ω or less). If the circuit is not closed, the conversion cable should be replaced.