STARTER SYSTEM DIAGNOSIS AND SERVICE

1. STARTER SYSTEM DIAGNOSIS AND SERVICE

2. STARTING SYSTEM COMPONENTS • BATTERY • CABLES AND WIRING • IGNITION SWITCH • NEUTRAL SAFETY SWITCH • STARTER TEMPERATURE SWITCH (if used) • STARTER RELAY • STARTER SOLENOID • STARTER MOTOR

3. TYPICAL STARTER MALFUNCTIONS • FOUR CATEGORIES • NO CRANK • SLOW CRANK • STARTER SPINS BUT NO CRANK • EXCESSIVE NOISE WHILE CRANKING

4. TROUBLESHOOTING • PERFORM BATTERY TESTING • CLEAN BATTERY TERMINALS AND CABLE ENDS • VERIFY ENGINE CONDITION IF NO CRANK OR SLOW CRANK • PERFORM CRANKING CIRCUIT VOLTAGE DROP TEST • PERFORM CRANKING CONTROL CIRCUIT VOLTAGE DROP TEST • MEASURE STARTER CURRENT DRAW, AND CRANKING SPEED

5. CRANKING CIRCUIT TEST • USE BATTERY LOAD TESTER AND CONNECT TO BATTERY TERMINAL ON STARTER SOLENOID AND STARTER GROUND TERMINAL • CONNECT DMM ACROSS POSITIVE CIRCUIT • CONNECT DMM ACROSS NEGATIVE CIRCUIT • DO NOT CONNECT DMM LEADS TO LOAD TESTER CLAMPS, DMM WILL NOT READ ACCURATELY • SET LOAD TESTER TO 500 AMPS FOR MULTIPLE BATTERIES OR ½ CCA RATING OF SINGLE BATTERY • VOLTAGE DROP TOTAL ALLOWED IS .5 VOLT MAXIMUM

6. PG 234 IN TEXT

7. TYPICALCRANKING CONTROL CIRCUIT PG 236 IN TEXT

8. CRANKING CONTROL CIRCUIT TESTING PG 237 IN TEXT • USE DMM TO TEST FOR VOLTAGE AT RELAY BATTERY TERMINAL, SHOULD READ BAT VOLTS • HOLD KEY IN CRANK POSITION, USE DMM TO TEST FOR VOLTAGE AT RELAY CONTROL TERMINAL, SHOULD READ BATTERY VOLTS • HOLD KEY IN CRANK POSITION, USE DMM TO TEST FOR VOLTAGE AT RELAY CONTROL GROUND TERMINAL, SHOULD READ 0 VOLTS • HOLD KEY IN CRANK POSITION, USE DMM TO TEST FOR VOLTAGE AT RELAY OUTPUT TERMINAL, SHOULD READ BATTERY VOLTS

9. TESTING NUETRAL START CIRCUIT PG 238 IN TEXT • DISCONNECT NUETRAL START SWITCH, HOLD KEY IN CRANK POSITION AND MEASURE VOLTAGE BETWEEN CONNECTOR AND GROUND, SHOULD READ BATTERY VOLTS • WITH SWITCH STILL DISCONNECTED CAN MEASURE OHMS WITH TRANS IN NUETRAL SHOULD READ NEAR 0, IF OL SWITCH IS BAD

10. TESTING STARTER TEMPERATURE SWITCH • STARTER MOTOR AT ROOM OR OUTSIDE TEMPERATURE • USE DMM AND MEASURE RESISTANCE BETWEEN THE TWO TERMINALS OF THE SWITCH • SWITCH IS GOOD IF RESISTANCE IS NEAR 0 • IF RESISTANCE IS HIGH SWITCH IS BAD

11. SOLENOID TESTING • CONNECT DMM ACROSS SOLENOID BATTERY TERMINAL AND STARTER MOTOR TERMINAL • DMM SHOULD BE READING BATTERY VOLTAGE • WATCH DMM, TURN IGNITION SWITCH TO CRANK POSITION, WHILE CRANKING DMM SHOULD READ LESS THAN .1 VOLT • IF VOLTAGE IS HIGHER THAN .1 VOLT SOLENOID DISC IS NOT MAKING GOOD CONNECTION TO BATTERY AND/OR MOTOR TERMINALS

12. STARTER TESTING ON THE VEHICLE • PERFORM STARTER CURRENT DRAW AND CRANKING SPEED TEST • RESULTS WILL VARY DEPENDING ON CONDITION OF ENGINE, BATTERIES, OUTSIDE TEMPERATURE, AND OIL VISCOSITY • USE INDUCTIVE CLAMP AMMETER • USE LASER TACHOMETER TO MEASURE CRANKSHAFT SPEED • CRANK ENGINE AND COMPARE MEASURMENTS TO SPECS IN SERVICE MANUAL

13. STARTER REMOVAL AND REINSTALLATION • DISCONNECT ALL BATTERY NEGATIVE CABLES! • IDENTIFY WIRES FOR RECONNECTION • PAY ATTENTION TO ANY MOUNTING SHIMS • CLEAN ALL WIRE TERMINALS, HARDWARE, AND STARTER MOUNT • INSTALL STARTER AND TEST FOR PROPER OPERATION, (ALSO CHECK FOR NUETRAL START, SHOULD NOT CRANK IN GEAR)

14. STARTER TESTING ON THE BENCH • SET OR CHECK PINION CLEARANCE • CONNECT STARTER WITH BATTERY CABLES, MUCH THE SAME AS ON THE VEHICLE • MAKE SURE ALL CONNECTIONS ARE TIGHT • USE REMOTE STARTER SWITCH TO ACTIVATE SOLENOID • USE INDUCTIVE CLAMP AMMETER TO MEASURE AMPERAGE DRAW AND LASER TACHOMETER TO MEASURE RPM • COMPARE READINGS TO SPECIFICATIONS IN SERVICE MANUAL

15. THE END