ACSGP

The OPC here couldn't diagnose any faults, and the alternator's charging fine.

rotorheadcase

Probably all the owner on this board have expreienced this at some point... I know I have it occur randomly and usually without any warning...

Neil

Rocket Rob

Its happened to me. There are a number of threads about this. Are you comfortable working with a volt/amp meter? A normal 964 will draw about 40 milliamps with everything off. If you have a interior or trunk light on, you can easily be pulling over 1 amp (1000 milliamps). This will drain your battery quickly.

https://rennlist.com/forums/964-foru...ght=power+fuse
https://rennlist.com/forums/964-foru...all-fuses.html

jimq

+1
It happens to me a couple times a year for no apparent reason.

jneteler

+1 Although it is usually after she has been ignored for awhile (~ 2 weeks or more).

JNeteler

911URGE

Did the OPC load test the battery?

Before spending the hours hunting for a high current draw I would take the battery to be load tested first. I had 2 cells in my Optima battery fail and replaced under warranty.

groovzilla

vip...i had thise happen months ago and solved the problem by replacing the interior light switches in the doorjam...i also changed out the rear decklid and front trunk..

**one way to determine if the interior light switches are problematiic is whether or not the lights are comming on when you open the doors??

mine wouldn't come on and the battery was draining after 3 days of sitting.

dan79brooklyn

Yes, recently fixed it. (I Hope) Mine was related to the interior light circuit which was not working properly. The trunk light was the problem as the wires were making contact with the body.

mojo747

Happened to me once. My battery is over 5 years old but it took a charge and is still seemingly ok..

Nine11

I left my radar detector plugged in and that did the trick...so did 3 weeks of sitting.

ilko

I have interior, engine, and trunk lights disabled. Door buzzers disabled. Basically anything that you don't need, get rid of it. The wiring gets brittle with age and stuff like that happens.

I also keep my car on a tender in the garage when I don't use it and that helps preserve the battery as well.

Nine11

I do that now as well....

jimq

I keep the glove box, engine and trunk lights unpluged. Its simple to reconnect ii they are needed. I am always leaving the trunk or engine hood open in the garage for one reason or another so it is cheap insurance I wont forget the light is on.

polar964

2 - 3 wks standing idle will drain the battery. Just cranking the engine puts a huge load on the battery when starting. When i intend to not use the 964 for more than a week i always connect a battery conditioner. Makes a huge noticable difference even on start up. More often than not it catches first time!

groovzilla

my 964 stays idle in the garage for sometimes 5 weeks and i have no problem with battery drain...my 993 was idle for 2 months with no problem...