Dash lights w/ failed alternator?

[Kneale Brownson]

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Deteriorating splice in the alternator-to-battery cable?


At 07:34 PM 09/04/2002 -0500, Robert Deis wrote:


>Patient is 86 5kTQw.
>
>Driving home yesterday, the little voltmeter I have hooked up to the
>cigarette lighter varied a lot between 11.0 and 12.5 or so volts. This
>seemed to correlate with the load on the system (i.e. whether the radiator
>fan was on, etc) but its hard to tell for sure.
>
>Then without warning, the voltage began to steadily drop until it was so
>low the sensors were giving confused readings and the car barely ran.  I
>coasted into an auto parts store and they charged the battery for me and
>sold me a new alternator.
>
>The charge in the battery got me another 6-7 miles (to my in-law's house)
>Voltage dropped from 12.8 to 10.1 along the way.
>
>I swapped the alternator there and drove the 70 miles home. Voltage varied
>between 12.8 and 12.0 along the way home, but the dash lights wouldn't
>work.
>
>Went to start it this morning and the battery was dead- 2.5 volts at the
>posts.
>
>Jump started it with a good battery, and everything seemed fine- dash
>lights were working, too, and I measured 13V at the posts, and maybe 14 at
>the alternator (crummy voltmeter..)
>
>Shut it off, waited for a little while, and the dash lights stopped
>working again- any battery voltage dropped to 2.5 again.
>
>What's going on here?  Can you tell me where to start?
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