94 Sport-battery not staying charged

[DaMiKe2d]

I have had this issue for the past year and cannot find a fix. The only way to get my 94 Explorer Sport to start is if I jump it off. I have a brand new 10 year battery from Costco, the alternator tested good, and I changed out the entire battery cables from the battery to the starter.

The truck runs fine when it is started but as soon as I turn it off, it will not start right afterwards. I was thinking there could be a drain and removed the radio bc it stopped working around the same time this started happening. My 2 year old put pennies in the CD player and a little bit after that I smelt a burning smell. As I said I removed it and taped up the wires to make sure nothing was touching but this didn't work either. The burning smell only happened that one time.

I am unsure of where to continue. Sounds like a huge pain to follow every electrical component and I'd probably end up tearing everything up doing that. I was going to do the test light thing on the battery but everyone I talk to says if it was a drain that it wouldn't be immediate and that fast, as in as soon as I turn the truck off and try to restart it. But it definitely kills the battery each time for some reason. They have told me 2 times in the past year that it was an bad battery but I cannot see that being the case.

If no one has a solution, any ideas of an expert place to take it to get checked in Atlanta? Everywhere I read, people say they get the runaround and they can never find the exact problem when it comes to the charging system.

Thanks in advance guys! I'm a newbie here but have always loved the advice this site has provided.

 

[Roadrunner777]

Check fuse #15 for starters, it supplies stator power to the alternator.

 

[Anime]

If it's a charging issue, generally it's either a case of the alternator not working, or some issue with the alternator not being connected to the battery, hence not charging even if the alternator itself is fine.

If the voltage gauge needle reads over to the right side with the engine running, that should mean the battery is getting 12-14+ volts and charging but not always.

A good test is to use a multimeter/voltage meter and check the battery voltage at the terminals with the vehicle off (should be 12.1-12.4V or so), then start the vehicle, and check the voltage again. It should be 14.4-14.7V if the alternator is charging the battery.

If the voltage is ~12V with the engine running, there is probably a disconnect somewhere in the wiring that connects the alternator to the battery. Usually the battery idiot light will indicate this, but if the bulb is burnt out, of course the light never comes on.

You should check everything from the terminals and wiring that are attached to the alternator, along with every inch of the wiring that goes from it to the battery. It may be as simple as a loose wire that came out of a connector, or might even be damaged wiring that was overlooked when you replaced the battery to starter cables.

If the alternator is the original one from the factory, and the mileage is high (150-200K+), then the brushes on the voltage regulator might be worn down, or the voltage regulator itself might be going bad, just enough to affect charging but not enough to throw off the gauges or idiot lights. If nothing else turns up, I would probably suggest throwing on a new alternator, just to check if that is the easy solution.


Also, are you sure the starting issue is because of the battery being low? The starter brushes on these do wear out too. If you get a *click* when turning the key, that's usually the starter. Giving the starter a whack with your fist or a block of wood or rubber hammer from under the vehicle can nudge the starter brushes inside it, and give enough contact for another start.

Starting issues from a low battery would usually be characterized by slow starting.

You can use the voltage test here as well, if the battery voltage is above 12V, but it won't start, it's probably something else. If you give the starter a whack and it immediately starts after that, you've found the problem. You can get a brush assembly for not much $ if you want to replace the brush assembly in the starter rather than replace the whole thing with a cheaper unit.

 

[larrydd999]

What happens when you turn the headlights on, then try to start? Do the headlights stay bright or do they dim? That's a quick test for battery voltage drop due to the starter (I don't always trust the dash voltmeter). If you have help and a digital multimeter (DMM) you can monitor the battery voltage when you turn the key. If little or no voltage drop (from about 12.1 - 12.4 or so with a good charged battery) then the problem is not the battery - maybe the start relay by the battery (I always replace it when replacing the starter and if I have ANY question about the starting circuit).

 

[gmbroy]

if your alt. has tested good & your battery is good I would check fuses first , or with it running check to see if you are getting 14.? at the battery . Do both of these first & let us know the results !!

 

[Roadrunner777]

Pretty much any shadetree mechanic will be able to figure this out, or yourself if you get a $10 voltmeter and figure out how to use it.

There are two things, though, that they might miss. They have both been found to be there problem here in the forums after a lot of fruitless searching:

Fuse #15 must be good to supply voltage to the alternator. Alternators need a little bit of power to start making power. Many an alternator has been replaced when a 25 cent fuse was the cause.

And, here is one that I bet few people know, but the forum moderator posted a few years ago: The idiot charge light is part of the circuit. If it is burned out, the system will not charge.

Not much more to say until you post more information... Best of Luck!

 

[DaMiKe2d]

Pretty much any shadetree mechanic will be able to figure this out, or yourself if you get a $10 voltmeter and figure out how to use it.

There are two things, though, that they might miss. They have both been found to be there problem here in the forums after a lot of fruitless searching:

Fuse #15 must be good to supply voltage to the alternator. Alternators need a little bit of power to start making power. Many an alternator has been replaced when a 25 cent fuse was the cause.

And, here is one that I bet few people know, but the forum moderator posted a few years ago: The idiot charge light is part of the circuit. If it is burned out, the system will not charge.

Not much more to say until you post more information... Best of Luck!

When you say idiot charge light, what exactly do you mean? The red battery light that comes on when you turn it over?

Fuse 15 is good by the way. Going to get a voltmeter now to do what you guys have recommended.

Someone mentioned to check the connections of the battery cables I installed but I dont see it being that because I had the issue before I changed them (thats why I changed them).

The alternator was checked after this problem as well and was good. Its not the stock one, I put it in there about 4 years ago.

And could it really be the starter as others have suggested? It always starts right up if the battery is charged or jumped ( even though i have to wait about 3 minutes when jumping it).

Not an expert AT ALL when it comes to cars but have a decent idea of how they work lol

I'll post after I get the voltmeter. Thanks a ton for the help. And yeah I'll try the headlights as well, just a pain to keep jumping it off so I'll do it once I get the meter.

 

[Roadrunner777]

Yes, the red battery light. Get your voltage readings, it's the right place to start, in my opinion.

 

[DaMiKe2d]

Alright, Got it jumped off, (the Idiot light does work by the way) and the meter was initially reading 14.4V then after about 5 minutes started to started to stay at 13.8. With the headlights on it reads 13.2. Left it running for about 20 minutes and then I turned the car off and it read 12V and then hovered around 11.8. But then surprisingly it did start back up when I tried a minute later. Then it stayed right around 13V.

Left it running for the past 20 minutes again and just checked and it was reading 13.6. Cut it off and its at 12.1 and slowly dropped to 11.9. And then it started again after leaving it off for about 15 minutes while it maintained the 11.9. I'll check back in a few hours I guess and then maybe conclude there is a slow drain if it drops too low to not start??

I apologize if this was just too much unnecessary info just making sure I let you guys know exactly what I did. Maybe I did fix the drain by removing the radio yesterday but I just didnt let it run long enough to charge the battery back up.... I dont know, we'll see if it starts later and tomorrow if it does start.... But any other possibilities and/or suggestions are welcomed in the meantime.

Thanks Everyone!

 

[gmbroy]

roadrunner The red light was a new one for me . I will keep that one in mind . Never to proud to learn .

 

[DaMiKe2d]

Just tried to start it again (almost 2 hours later) and started right up. Just installed some flowmasters too but haven't been able to enjoy them, maybe now I can!! Love my explorer! Let you guys know if it's good tomorrow.

 

[pkn]

I've had similar problem a year or two back (turned out to be the battery dying of age), bought then this little $15 voltmeter thingy - http://www.amazon.com/gp/product/B007Q2HOYK - and, you know, It does help bringing some confidence.

 

[larrydd999]

If you're seeing the battery voltage continue to drop below 12 Volts with the engine off, there's a circuit that should be off but is still on. There are other tests you can make, and if you learn how to use your DMM in the DC current mode you can do them, but it's a bit hard to tell you how to do that in this forum because I would need to sketch while I described it (I don't mean any disrespect by saying this, perhaps someone could explain it better than I).
One way would be to pull the various relays one at a time and see if the DMM voltage goes back to 12+ which it should with a good battery. Obviously this won't work if the problem doesn't involve a relay.

 

[pkn]

If you're seeing the battery voltage continue to drop below 12 Volts with the engine off, there's a circuit that should be off but is still on.

True, but only if the battery is good - good in both taking charge and holding charge, and fully charged.

From what I can see, neither is confidently confirmed yet... I understand that chances for brand new battery to be bad are slim, but they are not nil. If the problem persists, I would bring the battery to autoparts store were they do free battery test.

 

[littlebro294]

You would be surprised on what they do at an auto parts store. Batteries are rotated and have new dates put on them, so your battery could be 2 years old already and you wouldn't know.

 

[DaMiKe2d]

Truck started again this morning. Its holding charge way longer than it ever did in the past year. I'm not getting my hopes up that its completely fixed but I'm about 90 percent sure it is.

But isnt it plausible that the issue was a drain due to the radio and that was the problem? No one has confirmed that this could have been it.

Also someone mentioned to go ahead and change the starter relay when changing the battery and yes I did do this when I was changing the battery and the cables, it was cheap so i was like why not. Shouldn't have issues with the charging system for a while bc it seems like I've changed everything but if I do I'll know where to look and what to do thanks to you guys.

 

[Roadrunner777]

I didn't think the radio was a factor because you said you cut the leads. Let's just say this:

The batteries that fit the Explorer have a reserve capacity of 100 to 130 minutes at 25 amps, depending on the model of the battery. Let's call it 2 hours.

The last few radios I have purchased had an integral fuse for 10 Amps. There is some safety margin in that, let's say at full tilt, my radio draws 5 amps. I have a plain old kenwood in dash radio, no amps.

(math math math)

So, at full tilt, I should be able to play my radio for 10 hours, before I start having trouble starting the engine.

If your radio were damaged and drawing current, then maybe you get 5 hours at 10 amps. If it were more than 10 amps, your fuse would have blown (or you would have started melting insulation off wires). The stock radio is fused by the interior fuseblock, and I don't recall off the top of my head what size it is, but it's in that neighborhood.

Yes, it is plausible that your damaged radio was causing enough discharge to drain your battery, say, overnight.


Your readings do lead me to believe that you have a marginal battery or some power drain. It's good enough for a shop not to have to replace it, but it is still borderline. And, in warmer climates (and I have lived in Atlanta in July, they don't call it Hotlanta for nothing!) in warmer climates, batteries fail sooner. Electrolyte evaporates more quickly, hot starters drawer more current, battery cables less effective, etc... If you are happy, I'm happy, don't feel obligated.

But, the thing is, a sitting battery should be at 12.6V, give or take a little. A battery with some age will read less. My battery came with the truck 5 years ago. It has been sitting for about 6 hours after my last drive, and I did sit listening to the radio for a while before I took this measurement, I got 12.4 V.

So, I think you have a borderline battery or still have a current drain. The easiest way to figure it out is if you can get another battery for a temporary test. That will tell you everything.

(By the way, this doesn't really apply in this particular case, but if you are measuring for current drain, be aware that there is a light on the underside of the hood, and if it is still working, you have to account for it).

 

[Roadrunner777]

You would be surprised on what they do at an auto parts store. Batteries are rotated and have new dates put on them, so your battery could be 2 years old already and you wouldn't know.

I worked for a year at a tire and battery place... we were instructed to take the 'bad' batteries that were taken in, and charge them overnight. If they passed a very brief and lenient amperage test, we were to paint them black and put a remanufactured sticker on them. Don't ask, they are now out of business.