1997 S320 Battery Light - Transmiision Shift

Today while drinving my red battery dash light came on. I noticed the stereo then going on and off. Then next time I drove the car the transmission stays
in first, no shifting......engine runs fine.
So, is this a charging issue with the alternator or do I just need a new battery? Any input would be helpful before I have to call Hans and Frans.....
Thanks,
Harman
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Measure the voltage while your engine is running... You should get 14.4 V if you got a perfect alternator. The minimum voltage is 13.5 V... anything lower won't charge your battery.
If your battery is old, it might be time to change it. Any competent mechanic can run a load test on your electrical system to tell what might be at fault. Even your auto part store such as Pep Boys or Autozone.
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It sounds like the computer has gone into Limp Home mode for some reason (I believe that in LH the maximum speed is 30MPH - so perhaps this is why it doesn't feel like it is shifting).

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The alternator is chargeing at 18.5 volts and cooked the battery (no water). So do I have to replace the alternator/battery or is there a external voltage regulator and leave the alternator, it has 93,000mi and I plan on keeping it.
HC
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Change your voltage regulator... $40 at http://www.mr-auto-parts.com
You should change your battery at this time too... after you replace the voltage regulator. I suggest you buy Autozone battery... about $65 with 7 years warranty.
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I would change the battery first and then recheck the alternator output. It could be that your battery is DEAD and is shorting internally which is drawing too much current from the Alternator...
You might find the battery is the whole problem. Definitely recheck though, you don't want to smoke your new battery.
Marty
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A long time ago in Mn I looked all the batteries over and the highest energy battery was Sears Top of the Line, now called Gold or something like that. The high energy thingy holds in warm of chilly weather as I recall, having to do with the plate size and chemical content. Sears does not charge to check out your electrical charging system. If you need a new battery, they will check the system and install the new battery for less than half what Hanz und Franz charge. Plus you get a better battery. This is the first place that I deviated from using Hanz und Franz for service and I have not been sorry I did. Sears replacement lasted longer than the original (nocking on wood).
mcbrue highlychargedly under the bridge in the trailer down by the river
96 S420
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snipped-for-privacy@aol.com (MCBRUE) wrote in message

Well, 1 new battery and alternator later all is fine....thanks or all the input.
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