AvantS4me

I already have the replacement. Yes it's due, I have 106k miles. I was just wondering why...when I start the car the Alt is making 13.7 volts. It starts slowly going down. 13.69 68 67 and so forth. It levels off about 12.8 unless you turn something on. It always starts. It just bothers me. Any idea's?

S4_Cinci (I S'edTFA)

demands on the system. Now if the voltage increases when you turn on the A/C and fan then I would think it is working properly. When I have had alternators fail in the past, the voltage output could not keep up with accessories and the voltage would gradually drop unless the engine were revving pretty high, but even then it would not put out enough voltage to properly recharge the battery and run the other systems needing electric power. How quickly does it drop down to 12.8V? Is your battery fully charged (12.6V several hours after driving)? Sounds like a weak alt to me, but I haven't taken readings lately on a good one - my dash Voltmeter usually reads mid 13's at steady state.

quickaudi:STFA

efficient during the summer.
Usually, when I start my car I'm over 14 volts. During driving I'll get down to 13.x volts due to heat (no engine load due to A/C or headlights or etc.)

Honestly, at 106k miles, you've probably used up all of your brushes and they need to be replaced.