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13v Normal After Warms Up?

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Wanted to get your opinions after my mechanic said something:


Update: 996 C2 Cabrio (2000)


The issue/potential concern: After the car warms up (say after 20 mins or so) the voltage reading drops to approx 13V and pretty much stays there. I spoke to my mechanic about this and he said thats totally normally. However is it, seems abnormal to me?


Other than that the cars starts perfect each time and on cold starts always shows 14V.


Any thoughts/opinions as things I've read lead me to believe i should change the voltage regulator on the alternator?



Edited by singhmrp
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You never mentioned the year and model, which is always helpful in answering such questions, but in general these car's charging systems put out between 13.5 and 14.5V at idle.  It sounds like you may have one of two or three problems:  the battery is on its way out, or the voltage regulator is on its way out.  You may also have battery cables with high resistance.


I would have the battery and charging system load tested to see what they do under stress, then do a voltage drop test across the battery cables, and then proceed on the basis of those results.

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