Mechanics

ALTERNATOR ?

1993 Plymouth Acclaim

Electrical problem
1993 Plymouth Acclaim 4 cyl Front Wheel Drive Automatic 143368 miles

Initially I got a " Check Engine" light (lower right instrument panel), then the battery voltage meter dropped from 14V (normal indication since I purchased the vehicle in 2007) to 12V -- meter reads 8 at the lowest mark, and 18 at the highest mark with four tic marks in between, and finally I get a " Check Gauges" light (middle of the instrument panel). After the car sat for an hour or more, all the indications were clear. After about ten to fifteen minutes of running, all three indications came back. This occurred three times today. Then on the way home (about a three hour drive), the car died. I found a shop that charged the battery, and I was able to drive the car home.

How do I tell whether it is the alternator or the regulator (I was told the regulator is on the PCU board located outboard of the battery)?
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DWalser
March 6, 2009.




Hello –

My suggestion is to please go to Auto Zone (AZ) or O’Reilly’s (OR) and for FREE they can bring their tester out and check your battery and alternator.

Also, do you know how to check the codes on your car?

If you need to get back with me after you had your battery/alternator check, please make sure you tell me the size of your engine in liters.

Also, please check your belts to ensure they are in good condition and have the correct tension on them.

Thank you very much for the donation

Please let us know if what the final fix was for your car so we can better assist others. Thanks!

Find a car repair manual for your car repair questions.
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ImpalaSS
Mar 6, 2009.
Hello ..thanks for the donation ... much appreciated

Hope this helps .. let me know

The PCM monitors critical inputs to control fuel injection, ignition, emission and other engine management functions. The PCM has also been programmed to monitor several charging system related circuits.
Battery Feed To PCM
Alternator Field Control
Battery Charging Voltage (High And Low)
If a problem is sensed in a monitored circuit, a fault code is stored in the PCM's memory and the CHECK ENGINE light will be turned on (with a few exceptions). Fault codes can be read using the CHECK ENGINE light or with the Chrysler Diagnostic Readout Box-II (DRB-II).
NOTE:Fault codes remain in memory for 50 engine starts. Fault is erased from memory if failure does not reoccur.

For certain fault codes, CHECK ENGINE light will illuminate and PCM will enter limp-in mode. In limp-in mode, PCM attempts to compensate for particular component failure by substituting information from other sources. This allows vehicle operation until proper repairs are made.
UNSTEADY OR LOW CHARGING
Check for loose alternator belt, defective alternator, and/or charging resistance too high. High resistance could be caused by loose alternator or engine ground wire, and/or corroded battery terminals.

NOTE:Only charging system-related codes are listed here. For engine-related codes, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

CHECK ENGINE Light Diagnostic Mode
Start engine (if possible). Move transmission shift lever through all positions, ending in Park. Turn A/C switch on and then off (if equipped).
Turn engine off. Without starting engine again, turn ignition on, off, on, off and on. CHECK ENGINE light will come on for 2 seconds as a bulb check, followed by fault codes. Record 2-digit fault codes as displayed by flashing CHECK ENGINE light.
For example, Code 23 is displayed as flash, flash, 4 second pause, then flash, flash, flash. After a slightly longer pause, any other codes stored are displayed in numerical order.
Once check engine light begins to flash fault codes, it cannot be stopped. Code 55 indicates end of fault code display. Go to step 1) to enter diagnostic mode again. For more information on vehicle self-diagnostics, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
Refer to CHARGING SYSTEM FAULT CODES table to translate trouble fault code number to a circuit description (same description is displayed in DRB-II display). Once trouble area is identified, refer to appropriate charging system tests under TESTING (ON-VEHICLE) .

CHARGING SYSTEM FAULT CODES
Fault Code/Circuit Description/CHECK ENGINE Light On
12...........Battery Feed To PCM..............No
41 (1)..... Alternator Field Control...........Yes
44 (1) (2).. Battery Temp. Sensor..........Yes
46 (1)...... High Battery Voltage.............Yes
47 (1)....... Low Battery Voltage............Yes
55............End Of Diagnostic Mode.........No
(1)This code will cause limp-in mode.
(2)Sensor is inside PCM. If faulty, replace PCM.


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Dave H
Mar 6, 2009.

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