augsburg911

I was speaking to a family member of mine who also owns a 964, and he has experienced the same problem with his car, that I am having with mine. The battery will drain down, and not kick over, if parked for 2 or more days. When I turn my car off I hear a faint humming sound. I believe it might be from the after market stereo system, put in by the PO. I am going to use a battery test light to see if this is the problem. My question, has anyone experienced a battery drain (car not starting) after being parked for a few days?

dfinnegan

You may be hearing the CCU temperature sensor fan. That has been known to fail in the "on" mode. Try pulling that fuse.

augsburg911

Thanks, I'll give it a try.

Smokin

There are a lot of reasons for battery drain. A search here will turn up plenty... How old is your battery?

I was irked a few months ago because my Optima battery was needing a topping off every few days. I keep a battery tender on it but I thought I had just replaced it 2 years before and I couldn't believe it was the battery so I started looking elsewhere. I checked my receipt for the battery and it was 5 years old! I took it back and got a partial refund against a new one and now I don't have a problem unless I let it sit for over two to three weeks.

groovzilla

since i just experienced this with my car i thought i should mention:

1. check the interior door light switches in both pillars...are the lights comming on when door is open?...if not they could be shorting...
...same is true for front trunk and front hood light switches

**front hood switch also rests against a small piece of metal when hood is shut and sometimes this piece of metal gets bent downward and does not turn the light off....replacing the pillar switches cured my drain problem..

2. there are several threads about checking draw on battery and you should check that also to help determine source using a difital ampmeter...

newsboy

You don't say how old your battery is. You can take it to Sears, and they will test it for you to determine if it needs replacement.

augsburg911

Thanks for all your suggestions, I will give them a try. The battery was manufactured 0n 05/2008. I purchsaed a new one, and now I leave the negative cable off, until I can figure what the cause of the drain is from.

Marc Shaw

What a coincidence - I just got back from WallyMart buying another Optima Red 35/75 to replace mine from 2005 as it would no longer hold a charge -- even with a trickle charger on all the time.

Marc