Can't get new alternator in?!

[KevinH1990]

Coolbreeze,

I'm assuming that you disconnected your battery to perform some electrical work. When I installed my 996 cluster which required a battery disconnect, I was experiencing the idle fluctuation you describe. I performed the following procedure:

DME Adaptation:
1. Switch the ignition on for 1 minute without starting the engine. Do not actuate accelerator pedal, be sure pedal is in the rest position (make sure the floor mat is not pushing on the accelerator).
2. Switch off the ignition for at least 10 seconds.

That took care of my idle fluctuation.

Since I can now monitor my voltage and oil pressure, I noticed that the voltage was usually a rock solid 14 when the car was running and a little less than 12 when the car was on, but the engine was off.

Then, about a month ago I noticed that the voltage dropped below 14 when I was idling at a light. Since I had the air conditioning on, I assumed that was the cause.

Another issue to consider is the age of your battery. I was hearing a lot of alternator noise on my 1996 Infiniti G20. I changed the serpentine belt and when that didn't fix the problem I was considering an alternator replacement. It turned out the battery was nearly dead and the alternator was screaming because it was overloaded trying to charge the battery. I had never heard of that before, but a new battery fixed the problem so I believe.