05Raptor

Hey guys,

I have a 2005 f150 5.4 with 115k miles.

For some reason, my battery keeps dying. It started about a half a year ago, when I let my truck sit for about a month without starting it, then it wouldn't start. I kind of expected that, because that's a long time for a truck to sit. But then it turned into not being able to last even a week, then it wouldn't even start twice in a day without a jump. At that point, I replaced the battery. It was fine for a while after that, but then the problem relapsed. Now I will start it and drive it around, turn it off, and immediately try to start it and the starter won't even turn over once. The windows will not even roll up without the engine on. After I shut the truck off, I hear a sort of clicking sound, and it sounds to me like the fuel pump keeps running after the truck is off, because it sounds like it's coming from the fuel cell. I don't think the pump has ever been replaced.

Any ideas on what the problem could be?

Thanks,
Connor

CKsBAT

Checked the alternator? Grounds can cause some of the issues, but not that quick.

PerryB

Probably a weak alternator.

Rlaws797

Have your battery load tested. Use the process of elimination to rule out the simple things first.

chris.c

Could have hurt the alternator trying to charge a battery with a bad cell? Or it could be a poor connection at the terminals.

05Raptor

I did that on the first battery, and it was low, so I replaced it. This battery is less than 6 months old... Could it really die that fast?

Rlaws797

It almost sounds like you have something causing a constant draw on your battery. Have you added anything aftermarket; specifically electrical!

haha

I have the same exact problem and sounds.
If it goes the weekend without being started Monday morning it's dead. When I go on vacation I disconnect the battery and there isnt a problem starting after reconnecting. I was getting a new battery every year (under warranty) thinking it was the battery.
I think it's my GPS being on all the time. Sounds silly but 2 weeks ago we drove my wife's car all weekend and I didnt have a problem starting after the truck sitting for 2 days with the GPS off. So far this is my thinking.
The next step if it happens again is putting in a new alternator which I thought it maybe the problem until the GPS test.

lewissa81

I would at least have the alternator tested. Sometimes the auto parts stores machines will tell you an alternator is good, when it's bad though. It may be worth while to just replace it.
As for the noise you hear, I don't know. If the pump is still running, it's not because of the pump itself. There has to be a signal for the pump to run. That means either the wiring, a relay, or the ignition switch is suspect.

homer

Check the alternator but remember everytime you boost your battery you shorten the life on it... The first question I'll ask: Do you have a remote start and/or alarm? Is it 2-way? If so, believe it or not some of them draw enough power over a 2-3 week period to drain your battery dead. If that was the case, over time, each time you boost your truck you're shortening the life of the battery due to a quick charge (evaporating, etc). I try when I can to use a slower charge in those cases but obviously that's not always possible. When the battery gets really weak, now you're adding load to your alternator (and each time you boost).


I run Compustar Pro series remote start + alarms in both my F150 and my Fusion. The draw isn't that much, it's only 250ma, however 250ma x 24 hours = 6 Amps, 6 Amps x 14 days (2 weeks) = 84 amps... Your battery capacity probably isn't that much and in the cold you're going to need a reasonable amount still charged in order to start (and, the battery will freeze as it discharges in the cold as it turns back into water during the process).


I'm only guessing here but it's very possible. The remote start + alarms don't really go into a sleep mode like the Ford computer as they're probing and listening on the antenna. The remote starts aren't as bad but the long range ones still draw more power.


I have to put my truck on a trickle charger if I leave for a period of time. My car, I've added a solar panel to the back so I haven't really encountered the issue on that one anymore.



Let us know if you do have an aftermarket remote start + alarm, or anything else aftermarket. From there, you if you have a voltmeter, check the voltage before, check it while starting (have someone start it - see the drop), check it while running. While running expect to see 13.5-14.5, then add some load to it.. turn the heat to full, headlights on, measure again to see if it's 13.5-14.5. You can go further with an ammeter but if you don't have one it's probably easier to take your alternator out and have it tested as Lewissa and others have mentioned.


Hope this helps.