Car won't start even w/ new battery

A few weeks ago, my '98 Legacy Outback (170k) wouldn’t start up. I removed the battery, took in town, and bought a new one. The guys at the store tested the battery and indicated that it was completely dead, as expected. I installed the new battery and ran the car a bit just fine.

I had no need to run the car for the next few weeks, and when I went out to start it yesterday, it wouldn’t start at all. There was no response from turning the key. So I jumped it, and it seemed to run just fine.

After driving it for about 40 minutes, I turned it off and, again, the car wouldn’t start. After jumping it, it started up immediately.

My assumption is that it’s some part of the electrical system like the alternator, but I don’t know how to confirm that. If it’s something that can be fixed at home, I’d like to try my hand at it.

Couple other notes -

After the most recent attempt to start the car (unsuccessfully), I noticed a strange rattling noise coming from the driver side dash area.

Most likely completely unrelated, but I’ve lost a lot of tension in the parking brake recently.

Jump start your car and take the whole car to an auto parts place, like Autozone, or Pepboys. Ask them to run a charging system diagnostics to see where the problem is.

They will hook up a box to your car and ask you to turn the car on and off a bunch of times, and will test the alternator output, and the starter strength.


A pretty good way of troubleshooting your alternator with no meter is to wait until about dusk or dark, start your car turn your head lights on. With your car running, pay attention to how bright your head lights are. Now have someone shut off your car while you are still looking at your headlights. If the head lights get dimmer, your alternator is working (some). If they stay the same brightness as when your car was running, your alternator is not working. That is not high tech troubleshooting, but it is a good layman’s way of determining whether or not your alternator is bad.

Thanks! I contacted my local Autozone and they confirmed they can do this. When it stops raining, I’ll jump my car and take it down. I assume part of the implicit agreement here is that I’ll buy my new parts from these guys (which I’m happy to do). Should I expect any additional charges for this service?

A charged battery should not go dead from just sitting in a few weeks time, UNLESS there is a draw on the battery. Even though you have everything turned off, something is drawing current out of the battery when it is just sitting. If the battery was going dead when you were useing the vehicle this would most likely be be an alternator, chargeing problem etc, but you say this one went dead when you were NOT useing it. Have your mechanic check for a draw…

New battery may have been in want of a full charge but enough to start you when they put it in. That happens. Best to buy batteries where they go out the front door as fast as the trucks can deliver at the back door. Have the alternator’s output checked. That’s quick, easy and usually costs nothing. It’s not complicated. Either your alternator is or is not putting out correctly. Without a good alternator, your new battery may have lost what little oomph it had when you drove home. Actually, if you have a bad alternator, your old battery may have been dead but in need of charging. Next time, the question is not is the battery dead, the question is will it hold a charge.

Yes they will assure you that this will fix your problem if you buy the part. My mechanic might give me a break if he was wrong but once sold these folks will not give you a break(normally). There is no additional charge but since you expect a fix… It seems from your message that you do not drive often. Cars these days develop non visible drains on the battery for reasons that are difficult to diagnose. One solution is to disconnect the battery when you are not going to use the car for a few days. Otherwise get a battery charger for $20 to bump your new battery when it gets low in the mean time. You could always try to find the drain by testing the car and pulling fuses until you find the problem. But if you knew how you would have tried this already.

Newer cars can kill a battery in a couple months of just sitting. You have several constant draws on the battery that all take their toll: computers, radio presets, clock, and anything you might leave plugged in all can drain the battery.
Your best bet is to either disconnect the battery when you won’t be driving it for a period of time or (even better) invest in a trickle charger that will constantly charge your battery and can be installed with a quick-connect system for when you are ready to drive.
Something else to check is the battery cables and terminals, if they are the least bit loose the battery can be fully charged and not be able to supply power to the starter. Also check them and make sure they are completely clean and corrosion free when you hook them up.