1998 Chrylser Sebring Voltage regulator
Hello I replaced an alternator on this 98 Chrysler sebring 2.5 about two and a half months ago and the first one didn't work at all so I exchanged it and that one has worked fine all this time until now. Once again I am having issues with the voltage light coming on and the alternator whinning really loudly like it's under to much load. I've tested the battery several times, charged it back up after each alternator change and the battery seems good but getting drained down since the voltage it all over the place with this alternator. Could this be the alternator once again or is this going to be the computer since this is regulated in the PCM?
Cars & Trucks - Chrysler - Sebring - 1998 Chrysler Sebring
Answers & Comments
All I can tell you is that when the regulators in the PCM mess up, the alternator usually will not charge at all.
I do not know what you mean by "all over the place", but I can also tell you that if your charging system voltage is really erratic, like 12 volts one minute and nearly 15 volts the next, it is usually caused by a shorted (oe sulfated) battery cell. A shorted cell will cause the alternator to "full field" and make the whining noise you are describing. Also, shorted battery cells are what usually causes the early death of many alternators.
It could also be something as simple as a loose or "fretted" connection between the alternator and the PCM. I have fixed many intermittent problems by simply disconnecting and reconnecting the PCM connector.
Another way to help detect a malfunctioning PCM or bad connection to the PCM is to look at the charging system style="display:none;">It could also be something as simple as a loose or "fretted" connection between the alternator and the PCM. I have fixed many intermittent problems by simply disconnecting and reconnecting the PCM connector. Another way to help detect a malfunctioning PCM or bad connection to the PCM is to look at the charging system data with a scan tool while measuring the voltage at the battery with a digital meter and see how they compare. The computer should be "seeing" the same system voltage that the meter is reading at the battery. Also, what type of test are you performing on your battery? I have seen many of the newer batteries that will pass an old-fashioned load test, but will fail miserably when the battery impedence is tested (this is the sign of a partially shorted or sulfated cell).
Also, the most obvious thing (sorry, forgot to mention) is that you should also perform voltage drop tests on your battery cables. Anybody that has ever dealt with Chrysler Sebring charging system problems knows that they are notorious for corroded battery connections due to where the battery is located. You need to make sure that BOTH cables are clean and tight and check for voltage drops between the NEGATIVE battery post and the engine block as well as between the battery post and body. Then do the same for the POSITIVE post between the battery and starter and the battery and main fuse block.
If it is charging at all, the LAST thing I would suspect is the PCM.