AFTERCOOLER GP-AIR 3419505 - Caterpillar

5P6590 Tester Schematic
The illustration above is a schematic of the 5P6590 Wiring Harness Tester. Tests that can be made with this tester are as follows: 1 - Battery Voltage Test; 2a - Circuit Voltage Test By Use of Lamps; 2b - Circuit Voltage Test By Use of Meter; 3a - Circuit Continuity Test - Ground Seeking; 3b - Circuit Continuity Test - Short Seeking; 4 - Solenoid Test.Before each test, turn all switches to the OFF position, except for the BREAKER, which should always be in the ON position. If the machine has a RUN/NEUTRAL switch, it must be in the RUN position, and the machine disconnect switch must be in the ON position. Do not operate the engine while tests are made. If there is a power failure in the electrical system, be sure to check the fuses and circuit breakers of the machine.(1) Battery Voltage Test
(1) Always test the battery first, when troubleshooting an electrical system. A test of the battery will give a good indication of the amount of charge in the battery (or batteries). (2) Connect 1P2857 and 1P2858 Battery Lead Wires (1) to the terminals of meter (2) and batteries (3). With no load, an analysis can be made of the meter reading, for batteries connected in series for a 24V system. See the chart that follows. (3) If the battery charge is low, the battery must be charged.(4) If the battery charge is very low, a more thorough check must be made. Use either the 5P957 or 5P3514 Coolant and Battery Fluid Tester to check the specific gravity of the electrolyte in each battery cell. Use the findings of both the no-load test and the specific gravity test to get battery condition, according to the chart that follows. (2a) Circuit Voltage Test - Using Lamps
The test most used to check an electrical system for normal operation, is the circuit voltage test, where the lamps of the tester are used to show active circuits. When the test connections are made according to the procedure that follows, the test circuit will give a parallel circuit to the machine frame, through the lamps of the tester. When a test lamp lights (comes on), the serviceman knows there is voltage at that point in the machine electrical circuit, where the tester has been connected. The tester lamps are for use with a 24 volt system and, if outside light is bright, or if the electrical system has 10 volts or less, it is probable that the test lamp will not be bright enough to be seen. (1) Use the correct battery lead wire to connect the meter groun (-) terminal (1) to a good ground (2) on the machine frame as shown.(2) Use the correct test harness (3) (5P6598 for 16 pin connectors; 5P8561 for 10 pin connectors) to connect the machine wiring harness (4) test point to connector (5) on the tester.(3) Put LAMPS CONTROL SWITCH (6) in the ON position. As the machine circuits