Do I need a new Battery or a new Alternator?


I was driving my 2002 Ford Ranger

(150,000 miles) down the freeway yesterday,

and notice my battery light on the dashboard was sort of blinking on and off,

and then noticed my battery gage was reading “low”.

Fearing that I might get stranded in the middle of no-where, I drove the 10 miles home.

Once home, I turned the pick-up off, then

restarted it (it restarted with no problems),

and the battery gage was more back in the middle, and no blinking battery light

on the dash.

So I drove to work this morning, (it

started OK again). But by the time

I got to work (about 15 minutes), the

battery gage had begun to creep into the

“low” area again.

So it looks like something needs fixing/replacing. I’m afraid it might

die at any moment.

Normally, I’d automatically just go buy

a new battery. However, the battery is

fairly new: about 9 months old.

But there is always the change I bought

a defective one.

So does this sound like a battery problem,

or an alternator problem?



It could be neither and be a loose/damaged/corroded wires problem. Check & clean the battery terminals, and then all of the cable & wiring between battery & alternator. Pay special attention to the grounds.

If all of that checks out, just drive into any auto parts chain (e.g. advance/autozone) who will test your battery & charging system for free.

Could be a faulty alternator, bad grounds/battery cable(s), dirty connections.

Have a full (in vehicle) load test done on the charging system to locate the culprit.

Thinking alike cig. Oh well.

Check the wiring as was suggested, but it is most likely your alternator. (Why do car makers label it the battery light when it really means the alternator is failing?) Probably the brushes/slip ring are wearing out.

Well, you know - great minds and all of that. I saw in another post that you’re dumping your Silhouette. Say it ain’t so.

Most auto part stores will check your car’s battery and charging system for free. Why not let them do the test. Don’t be surprised if they say both are OK as it could well be something else. From what you know now, or at least what we know, there is no way of knowing what the problem or problems may be.

In the old fan belt days this was a sign of a loose fan belt. If your Ranger has a serpentine belt make sure it is tight and not “glazed”. If you have a fan belt make sure it is tight enough. Your alternator may be slipping at higher speeds and turning enough at slower speeds to charge a little but not sufficient to recharge the battery.

The charge light (gauge) shows the push-push contest taking place between the battery and the alternator. The alternator is winning (has more voltage than the battery) when the gauge shows “charge”. Poor wire contacts on the battery, or the alternator, can upset the balance of power.
Disconnect the battery cables, and the alternator cables, and, using a round file, a round wire brush, or sand paper remove the corrosion from the terminals. Swab the cable ends and battery terminals (posts) with petroleum jelly, and re-attach the cables. Check, now, and see if SHE BANG!

You have been well directed. I would like to comment on your paragraph spacing.Usually people don’t space at all,you wrote a poem.

The brushes in the alternator are probably worn out. Intermittent flashing means that it’s a possibility.

Alright, It ain’t so.

Yep, I don’t have any use for it anymore. Aside from the infamous LIMG and the usual wear items, it hasn’t been too bad.

When we still had the Coleman hrdtp camper we used the van to jerk it down to Clearwater, Fla. and Myrtle Beach, SC three or for times a year. (it depended on our dollar)

I just spent $840 fixing it up to certify and emission test it so’s I can sell it. It isn’t worth much today but I’m accumulating too many vehicles.

I’m retired and have more time than money, but the wife and I decided we should downsize the vehicles, so now we have an '04 Toyota Matrix XR to save on gas.

The ‘02 Tahoe is a pig on fuel but it just sits for long spells as I only use it for pulling the 21’ travel trailer. It was never destined to be a daily driver here.

I agree.  BTW Poems are far easier to read than lacking any spacing paragraphs are good.  

Thanks for making it easier to read than most.