yo E,
If batty seems dead now;
does horn honk as usual?
do headlights & radio come on?
Has alternator belt been checked for proper tension?
When old batty was returned, was it tested by the parts store? (assuming it was at an auto parts store)
With the engine running at 2000 rpm, check the alternator output voltage. The voltage should be between 13.0 and 15.0 volts at batty terminals.
Loose or Weak Contact at Generator Harness Connector TSB 96-21-4 for 85-90 BRONCO II,86-93 Bronco & F Series, etc.
Source: by Ford via
http://web.archive.org/web/20101203175811/http://www.mustangforums.com/mustang-tsb/View-TSB/Year-1993/Model-Mustang/TSB-96-21-4/CHARGING-GENERATOR-DISCHARGE-LOOSE-OR-WEAK-CONTACT-AT-GENERATOR-HARNESS-CONNECTOR--WIRING-GENERATOR-HARNESS-CONNECTOR-DAMAGED-LOOSE-OR-WEAK-CONTACT.html
ISSUE:
When a generator fails, there are a few failure modes that may cause heat to be produced at the wiring harness-to-generator connector. This excess heat may damage the female terminals on the wiring harness, resulting in increased resistance. The increased resistance produces more heat. When the generator is replaced, the resistance produced by a damaged connector may damage the new generator and could result in a repeat repair, including installation of another generator. High resistance (caused by a damaged connector) will not go away until the damaged connector is replaced.
ACTION:
Visually inspect the harness-to-generator connector for damage (heat, corrosion, distortion and cracking) before installing a new generator. Install the Generator Wiring Harness Connector Kit (E5AZ-14305-AA) if the harness-to-generator connector is damaged.
The Generator Wiring Harness Connector Kit (E5AZ-14305-AA) contains the following:
- One (1) Red Wire Butt Connector
- Two (2) Yellow Wire Butt Connectors
- One (1) Wire Connector Assembly
- One (1) Instruction Sheet (I.S. 6849)
PART NUMBER PART NAME E5AZ-14305-AA Generator Wiring Harness Connector Kit
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No Crank; this is by Ford for later years, but it applies to your 89 BII
Drain Testing
Check for current drains on the battery in excess of 50 mA with all the electrical accessories off and the
vehicle
at rest. Current drains can be tested with the following procedure.
WARNING: DO NOT ATTEMPT THIS TEST ON A LEAD-ACID BATTERY THAT HAS RECENTLY BEEN RECHARGED.
CAUTION: Do not crank the engine or operate accessories that draw more than 10A. You could blow the fuse in the meter.
NOTE: Many computers draw 10 mA or more continuously.
NOTE: Use Rotunda 88 Multimeter 105-R0053 or equivalent between the battery positive or negative post and its respective cable.
NOTE: Steps 1-5 correspond to the numbers in the following illustration.
Insert the test leads in the input terminals shown.
Turn switch to mA/A DC.
Disconnect battery terminal and touch probes as shown.
Isolate circuit causing current drain by pulling out one fuse after another while reading the display.
Current reading will drop when the fuse on the bad circuit is pulled.
Reinstall fuse and test components (including connectors) of that circuit to find defective component(s).
Typically, a drain of approximately one amp can be attributed to an engine compartment lamp, glove compartment lamp, or luggage compartment lamp staying on continually. Other component failures or wiring shorts may be located by selectively pulling fuses or disconnecting fuse links to pinpoint the location of the current drain. When the current drain is found, the test lamp will go out or the meter reading will fall to an acceptable level. If the short is still not located, after checking all the fuses and fuse links, the drain may be due to the generator.
MIESK5 NOTE; Ford still ref to te alt as the gen
Test Conclusion
The current reading (current drain) should be less than 0.05 amps. If it exceeds 0.05 amps it indicates a constant current drain which could cause a discharged battery. Possible sources of current drain are vehicle l
amps (underhood, glove compartment, luggage compartment, etc.) that do not shut off properly.
If the drain is not caused by a vehicle lamp, remove the fuses from the interior fuse junction panel, one at a time, until the cause of the drain is located. If drain is still undetermined, remove fuses one at a time at the main fuse junction panel to find the problem circuit.
Electronic Drains Which Shut Off When the Battery Cable Is Disconnected
Repeat Steps 1 through 6 of the voltmeter drain testing.
Without starting engine, turn ignition on for a moment and then off. If applicable, wait one minute for the illuminated entry lamps to turn off.
Connect the voltmeter and read the voltage.
Test Conclusion
The current reading (current drain) should be less than 0.05 amps. If it exceeds 0.05 amps after a few minutes, and if this drain did not show in previous tests, the drain is most likely caused by a malfunctioning electronic component. As in previous tests, remove the fuses in interior fuse junction panel one at a time to locate the problem circuit.
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