DESCRIPTIONBosch starter is a permanent magnet motor design. A planetary gear system between the armature and pinion shaft makes it possible to increase torque and reduce starter size. The planetary gear drive is splined to both the armature shaft and overrunning clutch. Starter torque is transmitted to the overrunning clutch pinion through the planetary gears which provide higher rotational speeds. Starter has serviceable solenoid and gear and clutch assembly. Nippondenso starter is a 4-field, 4-brush 12-volt motor with a solenoid mounted within the housing. The unit has a 2-to-1 reduction gear set in a die cast aluminum housing. Starter has serviceable gear and clutch assembly only. If starter solenoid fails, entire starter motor must be replaced.
TROUBLE SHOOTINGSTARTER DOES NOT CRANK OR CRANKS SLOWLY Ensure battery is fully charged. Turn on headlights. Crank engine using ignition key. If starter fails to crank or cranks slowly then stops and headlights dim way down, proceed to AMPERAGE DRAW test. If starter fails to crank or cranks slowly and headlights dim slightly, proceed to STARTER RESISTANCE test under TESTING (ON-VEHICLE). If starter fails to crank engine and headlights do not dim, proceed to RELAY TEST under TESTING (ON-VEHICLE). NOTE: For additional trouble shooting information, refer to the TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.
TESTING (ON-VEHICLE)AMPERAGE DRAWNOTE: Ensure battery is fully charged and terminals are clean and tight. Perform a battery load test before proceeding. Using an inductive volt/ammeter type battery tester, clamp ammeter probe to positive battery cable. Connect positive voltmeter lead to positive battery post and negative lead to negative battery post. On 3.3L engine, disconnect coil pack harness connector. On 5.9L diesel engine, disconnect both wires at fuel solenoid on injection pump. On all other models, disconnect coil wire from distributor cap and attach to ground. Ensure that all vehicle accessories are off and transmission is in Neutral or Park. Crank engine using ignition key and observe exact reading on volt/ammeter. Readings should be as specified. See STARTER SPECIFICATIONS table in this article. If amperage is greater than specified or voltage is less than specified, check and repair wiring between battery and starter. If wiring is okay, turn engine by hand and check for ease of turning. If engine turns okay, proceed to STARTER RESISTANCE test below.
STARTER RESISTANCE Using a voltmeter that will indicate tenths of a volt, perform the following voltage drop tests. Crank engine and observe voltmeter readings with voltmeter connected at following locations: Positive lead to battery positive post and negative lead to battery terminal on starter. Positive lead to starter housing and negative lead to negative post on battery. Positive lead to battery negative post and negative lead to battery cable engine ground connection. If voltage reading is greater than.2 volt at any connection, repair or replace wiring, or repair starter-to-engine ground. If voltage readings are less than.2 volt at all connections, proceed to step 3). Connect voltmeter at following locations and observe readings: Positive lead to battery positive post and negative lead to positive cable clamp. Positive lead to battery negative post and negative lead to negative cable clamp. If either reading is greater than zero, repair or replace battery cables. If both readings are zero, proceed to step 4). Connect positive voltmeter lead to battery positive post and negative lead to starter solenoid battery terminal. If voltage reading is greater than.3 volt, repair or replace cable between starter and battery. If voltage reading is less than.3 volt, starter circuitry is okay and test is complete. Repair or replace starter.
RELAY TEST On automatic transmission/transaxle vehicles, put gear selector in Neutral or Park. On manual transmission/transaxle vehicles, put gear selector in Neutral. Set parking brake and block wheels. DO NOT remove relay connector. Using a 12-volt test light, check for power between starter relay battery terminal and ground. If power does not exist, repair wiring. If power exists, go to step 2). Using test light, check for power at ignition terminal on starter relay while a helper holds key in START position. If power does not exist, repair wiring between ignition switch and starter relay. If power exists, proceed to step 3). Reconnect jumper wire between battery and ignition terminals. Connect a second jumper wire between starter relay ground terminal and chassis ground. If engine cranks, starter relay is good. Check and repair poor ground connection between relay housing and mounting surface. On models with automatic transmission, inspect neutral safety switch for malfunction and transmission linkage for improper adjustment. SOLENOID TEST Connect a heavy jumper wire between battery and starter solenoid terminals on starter relay. If engine cranks, solenoid is okay. Proceed to RELAY TEST under TESTING (ON-VEHICLE). If engine does not crank, check and repair wiring between starter relay and starter. Repeat test. If engine still fails to crank, repair or replace starter.
Friday, February 19th, 2010 AT 6:27 PM