Alternator

[Edward FitzRandolph]

Good day everyone!

 

I have a question regarding the alternator on a 2004 Cayenne S with 165,000 miles which I bought when it had around 123,000 miles.

 

I have a feeling that the alternator is starting to get a little worn and without the history I don’t know that it’s ever been changed. As a new alternator for this truck is well over $1500 I I’m hoping to understand a bit about the electrical system before I just start replacing things that may or may not need to be replaced. Additionally, if there’s other components outside of the alternator that could be causing the symptoms I would like to get some insight on those as well.
 

 

Recently I’ve noticed the voltage gauge, which usually sits consistently at 14 V, sometimes dips as I’m coming to a stop to around 13 V and usually will go right back up to right around 14 V.  I have also noticed that sometimes the needle says just below 14 V so maybe at like 13.8 or so. Using a Samsung galaxy note 8 and an ODB adapter I have watched real time voltage while sitting and recording while driving. I’ve noticed that the voltage will range anywhere from 13.1 V to 14 V without any real rhyme or reason as to when it’s fluctuating the 0.9 V…meaning that outside it sometimes dropping to about 13 V when coming to a stop, the .9 V fluctuation happens when I’m driving down the road and also stopped.

 

There was also a couple of random times where the front passenger blinker indicated to be out on the dash, and when checking it wouldn’t blink. When I went to change it the filament was fine and when I put it back together it worked! Same thing with the drivers side brake light. Not sure that this is possibly alternator related or something else…

 

I’m just curious if anybody on here has experienced this before or if anybody with wisdom on the Cayenne has any thoughts or opinions about what might be going on here. I feel like the alternator might need to just be replaced, but again I want a better understanding of what might be going on before I just start replacing stuff.

 

Thank you!!

Edited October 24, 2021 by Edward FitzRandolph