frustrated with "charging system" (and sears auto)

[tbomb]

so i just got a new die hard battery in september (4 months ago), and everything was perfect. then for a couple months, my truck became my office, and id listen to the radio everyday for 8 hours and start the engine every hour for 5 minutes to charge up the battery. one day, at the end of the day, the "battery gauge" in the dash was a lil low (at about $30-40%), and the dash lights were dim until i stepped on the gas, then theyd light up (this happened a couple of times, but i stopped listening to the radio during the day after the first time.)

in the last couple of weeks, i would start my truck, the needle on the gauge would go to about 50-55%, and after about 10 minutes of driving it would drop to between 40-50% (unless i let it warm up - if i would just let it run for 10 minutes, it would drop to about 40% until i started to drive, then it would rise a little.) anyway, something isnt right somewhere. since it was a brand new battery, and the dash lights lit up when i stepped on the gas, i thought it was the alternator, but apparently not. that needle shouldnt be fluctuating like that.

i just got back from sears auto (they ran a "complete" charging system check for free.) the battery was showing voltage in the 13's, and when we started the engine and gave it a little gas, it topped out at 14.03 (which seemed a touch low i thought.) i dont know anything about alternators, but the guy said it was fine (though, i dont think this guy knew his ass from a hole in the ground.) so i called the sears auto where i bought it (different store), and the guy there who sounded like he knew a thing or 2 said i could try to bring it back to him and he would run some more tests individually on the components (and im wondering why the place tonight didnt do that), but he said if the alternator and the battery were both fine, i could have a short somewhere. how the hell do you find a short?!?!

sorry its so long, im just frustrated. can anybody offer any advice for me?

thanks.

 

[Robb]

That first guy was a little off. An Explorer should charge at about 14.5V at idle. This isn't really typical tho, a lot of alternators charge at around 13.8V or so at idle, so he may have not been knowledgable on what an X is supposed to do. And I am not sure how accurate his equipment was because a fully charged 6-cell battery should be about 12.6V (2.1V per cell). So, IMO, your alternator is running a bit low. BUT, starting an engine and letting it run for 5 minutes, then cutting off, then draining the battery for a hour......... is an excellent way to destroy a battery. Batteries don't like to be discharged often, so you may have done some damage to the battery also.

Hopefully, the second guy can give you a more accurate system check and let you know how to proceed.

Robb

 

[tbomb]

robb, thanks a lot. those numbers are gonna be helpful. the guy who i called from the place i originally bought the battery from said that 14.03 sounded right, but im gonna try to talk to him about it. the problem is that most shops have a policy not to replace a battery under warranty (like mine), unless the numbers dictate, and i guess they have a universal number that they use for every make of every car - so an explorer wouldnt be any different than a "le car", heh. so if i tell him it should be around 14.5, he'll prolly blow me off.

i could just go ahead and install a new alternator (which is what i was planning), but what if its not the alternator? then im out $166, and i still dont know what the problem is.

i didnt mention to either of them the situation at work where id drain the battery then start it up and so on and so forth - the guy who ran the tests tonight wouldnt have cared, and the guy on the phone wont remember the story when i go there on saturday, so ill tell him then.

heres my concern, though. battery issues = no problem. alternaotr issues = no problem. if theres a short somewhere, im gonna lose sleep could i possibly have a short somewhere? how the hell do you get a short anyway? i havent screwed with anything electrical?

 

[Robb]

To be honest with ya, I wouldn't even start thinking about a short at this point. Your dimming lights indicate to me to be a charging problem. That just sounds like to much draw (headlights) that the system can't handle.

I wouldn't mention to anybody the thing about running the radio all day at work. What they don't know won't hurt them. They may dig up the small print and tell you that you have "mistreated" your battery and therefore, it has no warranty.

Shorts can be caused by a lot of things, but your truck only being a few years old and you not doing anything electrical to it, I would doubt you have one. You can find them (or at least help find them) by using an amp meter in series with the battery and pulling fuses til the draw goes away. Again, I wouldn't bother with thinking about a short right now tho.

Robb

 

[tbomb]

Robb,

thanks again. the only reason i wanted to tell the guy about draining the battery and then letting it run for 5 min is because if i dont, he'll just tell me that nothing is wrong, based strictly on the numbers, when in reality, the numbers wont tell the whole story. the least of my concerns is that he wont give me a new battery for free under the warranty (though, ill never buy a battery from sears again.) i just want the problem fixed; splurging for a new battery if the guy screws me leaves a better taste in my mouth than them not finding anything wrong, even though i know that the battery isnt up to par.

as far as shorts, thanks - that puts my mind at ease. i dont know much about electrical stuff, and when he said i could have a short, i was in "pre-panic" mode, cuz i know electrical stuff (especially hunting for the problem) can get expensive, and since i know nothing about it, id prolly get ripped off. i couldnt imagine having one, since my truck is only 4 years old and has 48k on it.

heres what i spent the last half hour doing - poking around my ford cdrom. i dont know my way around it that well, but heres what i found:

"the voltage gauge reads high or low - 4.0L SOHC, 5.0L"

possible sources:
-generator (low output)
-voltage regulator
-voltage gauge
-instrument cluster wiring

so im thinking its either the alternator or the voltage regulator, but isnt the voltage regulator part of the alternator? so i guess its the alternator either way, right?

no matter what, i think im gonna wait until after this weekend to do anything. ill take it to sears on friday night and see what they say. then its going to ford on saturday for state inspection and emissions, so ill mention it to the service writer, who im sure will forget to mention it to the mechanic who deals with electrical stuff (i know that sounds cynical, but thats usually how it works.) and if it needs an alternator, i can do it next weekend.

it really sucks living in an apartment and having no means to work the truck, and my moms house is 100 miles away with my garage and all my tools and stuff.

robb, thanks again for your input. ive been around here long enough, to where most people know that when i find out something is a little "off" with my truck, i get a little nuts, heh. tonight, i really just needed some rational logic and reassurance to calm me down.

 

[Robb]

tbomb,
Just thought of something (wonders never cease). Did the guy that "checked" your system just take voltage readings or did he physically hook the battery up to a load tester? It he didn't, this may explain a lot.

When batteries go bad, or short a cell, or whatever.........they often do really weird things. It is a lot of complicated chemical crap. If he simply read the voltage of the battery, he might have only read "surface" voltage. Think of that as voltage with no gut behind it. Batteries can show correct voltage, but as soon as a load is placed on them, it drops like a rock. They make testers to specifically test for this, and if he didn't use one, he messed up. If you have a shorted cell (or some other battery problem) it could also explain why the alternator charging voltage wasn't right also. A bad battery could screw with the charging voltage of the alternator.

HEHE, now you got me leaning towards bad battery.

Make sure the 2nd guy runs a complete load test on the battery.

Robb

ps: I still wouldn't mention the "radio all day" thing. The only thing that would mess up is the battery and a load test of the battery would show it.

 

[Alec]

I had an Optima that surface and load tested perfectly. It wouldn't start the truck though.

I'm thinking either voltage regulator or you crapped the battery out.

 

[tbomb]

robb, he ran load tests on the battery with the machine he had.

though, i noticed something new today. i dont know what compelled me to do this, but with my windows up and my lights on, i tried closing my power windows (even though theyre already closed), ya know what i mean?...just hit the up part of the window swith while the windows are up. well, the needle on the "dash voltage gauge" dropped like a rock, and the dash lights got dim, and the rpms actually dropped, but went back to normal when i let go of the switch. i know its supossed do to that, but i dont think its supossed to do it to this degree.

if it turns out to be the voltage regulator, then i need a whole new alternator, right?

 

[Alec]

My lights dim when I do that window thing, but the voltage doesn't drop.

It is definately either your alt (or regulator) or battery.

 

[tbomb]

Originally posted by Alec
My lights dim when I do that window thing, but the voltage doesn't drop.

It is definately either your alt (or regulator) or battery.

excellent. now theres only one problem left to solve: which is it? the battery or the alternator? heh. the battery is only 4 months old, but like i said before, it could be screwy from the way i used it, or just a factory defect.

i was considering just buying an alternator and throwing it on, but thats prolly not the best idea, right?

 

[tbomb]

bump.

anyone have any last minute comments? as of right now, im prolly gonna throw a new alternator on this weekend; i really dont know what else to do. i can keep having different shops run different tests and crap like that, but by the time someone comes up with something, the problem could be bad enough that my truck wont start one morning.

thanks.