Alternator: Testing and Inspection

Tool Required:
J 41450-B Universal CS Generator Tester
To diagnose the CS 130D generator, use the following procedure:
1. Ignition switch "OFF". Turn all electrical accessory loads "OFF".
2. Turn load in carbon pile load tester all the way "OFF". Connect load test across battery terminals.

Important
^ Refer to wiring diagram to be sure the ammeter clip is placed for entire generator output to pass through clip. If circuits are split so that any of the current can pass through other parallel circuits, the generator output reading on the inductive ammeter will not be accurate unless all such circuits pass through this clip.

3. Install inductive ammeter around output wire(s) of generator.
4. Perform Universal Tester Self-Test procedure per manufacturer's instructions to verify proper operation of tester.
5. Connect red alligator clip of tester to generator Output terminal. Connect black clip to metal generator housing. Green "POWER" lamp on tester should light. If it does, go to step 8. If not, go to step 6.
6. Use Digital Multimeter (DMM) to check voltage between generator output terminal and battery negative terminal. If reading is B+ voltage, go to step 7. If not, check for open fusible link or other open condition in generator output wiring and repair as necessary. If the tester's green "POWER" lamp now lights when connected per step 5, go to step 8. If no open condition was found or the green "POWER" lamp still does not light, go to step 7.
7. With tester still connected as described in step 5, connect a jumper wire between the generator metal housing and the battery negative terminal. Green "POWER" lamp on tester should light. If it does, check ground path from generator housing to battery negative terminal for open conditions and repair as necessary. If the tester's green "POWER" lamp now lights, go to step 8. If not, return to step 1 and repeat procedure, including tester self-test procedure.
8. With tester still connected as described in step 5, disconnect 4-way generator connector from generator and connect matching connector on tester to generator. The red "DIAGNOSTIC" lamp on the tester should light. If it does, go to step 10, If it does not, go to step 9.
9. Disconnect 4-way tester connector from generator. With ignition key in "RUN" (engine stopped), use a fused jumper lead (with 5-amp fuse) and Metri-Pack 150 terminal probe adapter to ground the "L" terminal (cavity B) in vehicle harness 4-way connector. if fuse does not blow, replace the generator. If fuse blows, repair "L" terminal circuit (225) for direct short to B+ or mis-wired/no resistance condition, then replace generator. Fix wiring before replacing generator.
10. Turn "OFF" all electrical accessories and close doors, etc. to be sure all loads are off. With tester connected as described in step 8, start engine and let it idle briefly. (Note that the vehicle's generator control circuits are bypassed during this test, and the charge indicator in the instrument cluster will not operate normally.) After the engine starts, red DIAGNOSTIC" lamp on tester should not be lit. If it is still lit, replace the generator. If it is not lit, go to step 11.
11. Increase engine speed to 2500 rpm. The "DIAGNOSTIC" lamp on the tester should not light. If it lights, replace the generator. If it is not lit, go to step 12.
12. With engine speed still at 2500 rpm, turn the load on the carbon pile load tester to "ON" and adjust until the generator output is at the Load Test value listed in the Generator Usage Chart under Specifications. If the red "DIAGNOSTIC" lamp on the tester lights with the generator operating at or below the load test output value. Replace the generator. If the red light does not light and the load test value is attained, the generator is good. DO NOT replace the generator. Go to step 13.
13. Turn the carbon pile load tester load to "OFF" and stop the engine. Remove the generator tester, ammeter, and load tester from the vehicle. Reconnect the 4-way harness connector to the generation Be sure the connector is fully seated and latched.
^ If the vehicle charge indicator in the instrument cluster still does not operate correctly diagnose and repair the generator control circuit.
^ If the customer has commented about erratic or high voltage from a generator that uses an "S" terminal connection, be sure to check the "S" terminal circuit (cavity D in the harness connector) for intermittent or high resistance connections.
^ If the customer has commented about a battery that loses charge over a period of time, refer to Battery and check for abnormal parasitic loads. Battery