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My 2004 Ford Freestar frequently has to be jumped to start. Once jumped, if I drive it for more than 15 min or so, it'll stay charged enough that I can drive it again within the next day or so. If I leave it in the garage for two days or more, it won't start and needs to be jumped again.

I believed this was the alternator's fault, so I had it replaced. It didn't fix the problem. I had the battery checked at the auto parts store and they said it was good. They suggested something about the ground or that I might have something plugged into the cigarette lighter (I don't). I followed the ground wire at their suggestion and didn't see anything suspicious. The connectors are all pretty clean.

Suggestions?

UPDATE: I checked the voltage with my multimeter. With the car off, the battery registered about 12v, with the car running, it registered just over 14v. So my understanding now is that the battery and the alternator are probably not the problem?

The battery is one year old.

  • Was the battery load tested at the auto parts store, or just a quick voltage test? (load test is big machine/cart and voltage is a small hand-held tester). You can also check for a "parasitic load" with an ammeter. There are several questions that cover that once you know what to search for. – JPhi1618 Jan 31 '18 at 21:51
  • I am not sure. They put it in like a big drawer thing. – Ben Walker Jan 31 '18 at 21:53
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    Yea, that's probably a legitimate load testing rig. Testing the alternator while it's in the car is the next step. This can be as easy as measuring the battery voltage while the car is running. It should be around 14v if the alternator is charging the battery. – JPhi1618 Jan 31 '18 at 21:55
  • I have a multimeter. I'll try to figure out how to do that I guess. – Ben Walker Jan 31 '18 at 22:00
  • Should be super easy. Even if you hook up the (digital) meter backwards, you'll get a negative 14v, and still know that you're good. – JPhi1618 Jan 31 '18 at 22:01
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A good battery should hold charge when the vehicle is not running. If the alternator were the problem (not properly recharging), then I would expect similar problems after a short and a long period of stopping.

But if you can consistently start shortly after a drive, but not after a couple of days, then I would expect either

  • failed battery
  • parasitic current draw

I had a load test at the auto parts store give me an "OK" once on a battery, but replacing it fixed all the problems. So it's not impossible for the good bill of health on the battery to be incorrect. Do you know the age of the battery? If it's over three years old, I would be very suspicious of it being the problem.

Also, if you have a failure in something that can be energized (dome light, some radios, car computer, etc.) then it can draw excess power constantly. For a marginal battery, it doesn't take much over 48 hours to prevent it starting. Not sure of your 2004, but I'd be suspicious if it drew anything approaching 0.1A when everything is off, doors shut and locked.

  • I have replaced the battery twice in the last couple of years, for this same issue. It's one year old. The doors are frequently left open by my kids. I figured that was OK since there are not any lights that stay on while the doors are open. Could that possibly be the issue? – Ben Walker Feb 1 '18 at 15:56
  • Please put the age of the battery in the original question. For a 2004, you might be okay on open doors. But many more modern cars have much higher load when doors are open, with or without the lights being on. Only way to tell is to measure the draw directly. Do you have or can you borrow a clamp ammeter? – BowlOfRed Feb 1 '18 at 15:59
  • I do not have a clamp ammeter, not do I know any friends that do. I would buy an inexpensive one if it'll help me figure out/fix what's happening. – Ben Walker Feb 1 '18 at 16:16
  • You can use a multimeter as well, you just have to be really certain that you don't try to start the car when it's hooked up. popularmechanics.com/cars/car-technology/a5859/… – BowlOfRed Feb 1 '18 at 16:18
  • I think I can manage not accidentally starting the car ;) – Ben Walker Feb 1 '18 at 16:41

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