ALTERNATOR GROUP 1P7771 - Caterpillar

Note: Refer to Figure 1 in Illustration 4.
Note: Refer to Figure 3 in Illustration 4.
Note: Refer to Figure 4 in Illustration 4.
Note: Refer to Figure 9 in Illustration 4. Pressure Gauge Charts
Fuel Gauge Charts
Articulation Gauge Chart
Maintenance
Check and Calibrate the Analog Gauge Tester
The 189-1720 Analog Gauge Tester is calibrated at the factory, but may occasionally need to be recalibrated using a Digital Multimeter.1. Connect a Digital Multimeter to the two clips of the gauge tester.2. Turn the four dials all the way to the counterclockwise position.3. Use Chart A below to determine if each of the variable resistors are calibrated correctly. Turn "Dial 1" to the 25 Ohms setting and read the Digital Multimeter. The reading should be a minimum of 22.5 Ohms and a maximum of 27.5 Ohms ( 10% of the Calibration Point). For the most accurate test results, the Digital Multimeter's reading should be as close to 25 Ohms as possible. 4. To recalibrate "Dial 1":a. Turn "Dial 1" until a 25 Ohm reading is shown on the Digital Multimeter.b. Loosen the set screw on the dial using 9S-1742 Hex Key Wrench.c. Carefully turn the dial so the pointer (white dot) lines up with the 25 Ohm mark. Make sure the variable resistor's steel shaft does not move when the dial is turned.d. Tighten the set screw in the dial.5. Verify the calibration. Turn the dial completely counterclockwise and then back to the 25 Ohm mark. Recheck the reading on the digital multimeter and make sure it is within the specification range in Chart A.6. If necessary, repeat Steps 4 and 5. Continue this procedure for Dials 2, 3, and 4.Fuse Test/Replacement
If the Analog Gauge Tester is not operating, use a Digital Multimeter to check the output. Move the dials and if the output's resistance remains at 0 Ohms, then the fuse should be checked.1. To remove the fuse, turn fuse cap (5) to the left one-half turn and pull the fuse free.2. Use a Digital Multimeter to test the fuse.a. Set the Digital Multimeter on the 200 Ohm scale to check the continuity between the two legs of the fuse.b. If the fuse is good (reusable) the resistance will be less than 1 Ohm.c. A defective fuse will measure infinite Ohms (OL on the Digital Multimeter's display) and should be replaced.d. If the fuse is defective, install a 3AG, 5 AMP, Fast Blow Fuse as a replacement.Service
If the 189-1720 Analog Gauge Tester does not operate properly, then recalibrate it using the procedure in the "Calibrating the Analog Gauge Tester" section. If it continues to not operate properly, then contact the Caterpillar Service Technology Group (CSTG) for information on how to obtain the needed repair service.CSTG provides the instrument's user with a warranty of one year from purchase date. If the reason for failure is determined to be abuse, the warranty is declared void. Any out-of-warranty repairs will be charged to the owner.For any product support questions with your instrument, contact your Caterpillar contact or CSTG