Starters: Diagnosis Ford Thunderbird XI

TROUBLE SHOOTING

Verify customer concern by operating starting system. Check battery for state of charge. Check cable connections at battery and starter motor. Ensure transmission is fully engaged in Park or Neutral. Check fuse No. 21 (30-amp) in auxiliary junction box, located underhood. (Scheme 1) Check fuse No. 22 (20-amp) in battery junction box, located on right side of trunk. (Scheme 2) Check fuse No. 1 (5-amp) in central junction box, located under right side of instrument panel. (Scheme 3) If problem exists, repair as necessary. If problem does not exist, repair by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.

Scheme 1

Scheme 2

Scheme 3

TEST B: UNUSUAL STARTER NOISE

1. Verify starter is installed properly. Ensure bolts are tight. Repair as necessary and check system for normal operation. If starter is mounted properly, go to next step.
2. Connect remote starter switch between starter terminal "B" (Red wire) and starter motor terminal "S" (Gray wire). Engage starter motor and verify noise is coming from starter motor. If noise is coming from starter motor, go to next step. If noise is not coming from starter motor, diagnose engine mechanical concern. See appropriate article in ENGINES.
3. Remove starter motor. See «STARTER MOTOR»(ref-139232-S12913046732002042900000) under REMOVAL & INSTALLATION. Inspect flywheel ring gear for wear or damage. If ring gear is okay, replace starter motor. If ring gear is worn or damaged, replace ring gear and inspect starter drive gear. If drive gear is also damaged, replace starter motor.

ON-VEHICLE TESTING

VOLTAGE DROP TEST

Note. Make all DVOM connections at component terminal rather than at cable or wire end.

Scheme 4

1. Verify battery condition. Battery voltage should be 12 volts or more. Load test battery at approximately one-half cold cranking amperage rating. See load tester manufacturer's instructions. If battery voltage is less than 12 volts or loaded battery voltage is less than 9.6 volts, service battery or charging system as necessary.
2. Disconnect inertia fuel shutoff switch to disable fuel system. Connect remote starter switch between starter solenoid terminal "S" (Gray wire) and positive battery post. (Scheme 4)
3. Connect positive DVOM lead to positive battery post, and negative lead to solenoid terminal "M" (solenoid-to-motor connection).
4. Engage remote starter switch. DVOM should indicate.8 volt or less. If DVOM indicates more than.8 volt, go to next step. If DVOM indicates.8 volt or less, go to «STARTER GROUND CIRCUIT TEST»(ref-139232-S26757249442002042900000).
5. Move negative DVOM lead to solenoid terminal "B". Engage remote starter switch. If DVOM still indicates more than.8 volt at terminal "B", go to next step. If DVOM indicates less than.8 volt, solenoid connections or contacts are bad. Clean solenoid terminals "B", "S" and "M". Repeat steps 2 - 5. If DVOM still indicates more than.8 volt at terminal "M" and less than.8 volt at terminal "B", solenoid contacts are bad. Replace starter motor. See «STARTER MOTOR»(ref-139232-S12913046732002042900000) under REMOVAL & INSTALLATION.
6. Clean cables and connections at solenoid and battery. If DVOM still indicates more than.8 volt at terminal "B", replace battery cable. NOTE: To locate excessive voltage drop, move DVOM negative lead toward battery, and check each connection point. When high DVOM reading disappears, problem is between last connection point and previous connection point.

STARTER GROUND CIRCUIT TEST

Note. Make all DVOM connections at component terminal rather than at cable or wire end.

Scheme 5

1. Disconnect inertia fuel shutoff switch to disable fuel system. Connect remote starter switch between starter solenoid terminal "S" (Gray wire) and positive battery post. (Scheme 5) Using a digital DVOM set at lowest voltage scale, connect positive DVOM lead to starter housing, and negative lead to negative battery post.
2. Engage remote starter switch while observing DVOM. The DVOM should indicate.5 volt or less. If DVOM indicates more than.5 volt, clean negative cable connections at battery and chassis. Also clean engine ground cable connections at front cover and engine mount bracket. If voltage drop is still excessive, repair or replace negative battery cable and/or engine ground cable as necessary. Repeat starter circuit test after repair to ensure problem has been corrected. If battery and cables test okay and starter motor still cranks slowly or not at all, replace starter motor. See «STARTER MOTOR»(ref-139232-S12913046732002042900000) under REMOVAL & INSTALLATION.