Battery Light in car comes on sometimes...why?

[Abbott]

OK, perhaps this isn't the best forum for this, but people have on a few occasions made posts regarding computers, so why not?

I'm wondering why the battery light still comes on, though in only circumstances. To better illustrate the problem, I'll give some background, starting with when I first noticed the problem.

It first started coming on almost frequently, and I couldn't think of any good reason why. There also didn't appear to be any pattern or set of circumstances that cause it. So I took it into the dealer to get it checked. They said that the alternator belt (or something) needed to be replaced, so I told them that I wanted them to do that. Shortly thereafter, I took a road trip. I was frightened, since I noticed that the battery light came on again! Even worse, my speedometer failed a couple of times, but worked later. Both times that happened the ABS light came on. So I went to the dealer again. This time they said it was the "speed sensor," but couldn't give me a reason why battery light came on too. When I asked if the problems could be compounding themselves ("speed sensor" problem causing the battery light to turn on), I was told "Possibly." I hated that, because I want to hear "Yes" or "No." So I got that fixed. Everything appeared fine, until...

It was time to go on the road again. I rarely go on multiple day trips, but I often go out of town. Every time I go on the highway, I can almost count on it. The battery light comes on at some point, yet everything appears to remain functional. It never used to do that before, even while on the highway. There's also no pattern. Not when I hit a certain speed, amount of time being on the highway before it turns on, whatever. The only pattern or circumstance I notice is that this occurs when I'm on the highway.

Everything appears to work fine, except for the battery light coming on sometime when I'm on the highway.

Is there a reason for this? Is it indicative of a larger problem, just waiting to show up? The vehicle is a '99, by the way.

 

[Docs]

My engine light trips every 150ish km/80 miles. Does everything in my car work? Yep.

The day your car doesn't start, is the day it means something.
(and I'm no mechanic, but your alternator might be going, check your battery voltage )

 

[SmokeX]

If you alt is gone, to find out start the car and take of the negative battery part the black one. if it keeps running alt works. if not get a new one, will cause problems if you dont.

 

[wolf116]

test your batterys voltage with a multi-meter. needs to be around 12V.
Then start your car. It should go up to aroung 14V.
If not replace the alternator.

Is you car hard to start?

 

[spider_007]

what kind of car is it???

check the ground wire (make sure it's got good contact). on most cars it's screwd on the chassie near the hood latch.

 

[Abbott]

what kind of car is it???

check the ground wire (make sure it's got good contact). on most cars it's screwd on the chassie near the hood latch.

It's a '99 Ford Ranger. OK, technically it's a truck, but whatever. I've also had it since August '01, so I've had it for most of it's life. Before that, according to Carfax, it was part of a fleet of some sort. I don't know what fleet, I bought it used from a dealer. Plus, 13,500 some miles for three years since the date of manufacture wasn't bad.

I don't think it's the alternator. I had that replaced a couple years ago. I thought it might be the battery, since I can't remember if or when I replaced it. Well, apparently I did. The battery was new in Jan. '04, obviously newer than the Aug. '98 date of manufacture.

Wolf116:

No, I don't have get the feeling it's hard to start. It's a little harder if it's bitter cold, but I expect that's the case with any car.



Also, this only happens on the highway. Does this model, or perhaps cars in general, use more electricity on the highway? I don't see how, though I thought that perhaps electricity usage is somehow outstripping the alternator's capacity. I know that summer will be here before too long, and I'm going to need my A/C.


Perhaps I should use this excuse to ditch it and get a another, newer car. I'm not exactly proud I drive it, it rides rougher than my mother's Camry (which is probably lower middle-end), and it's certainly not something to show off to women, creating another hurdle as if I don't have enough (women would eventually find out what I drive). BUT, I'm not ready to get another car yet.

Anyway, I hope this isn't a Ford problem. If so, then no replacing it with a Mercury Grand Marquis (though it seems that nearly every police department uses the Crown Vic, which is mechanically the same), leaving only the Chrysler 300 (newer RWD version) as the only option, as G.M. doesn't make any 4-door RWD V8 cars for the U.S. market (they will in 2009, however). My parents have never owned a Ford, so there's no previous experience to build on.

 

[penkitten]

http://auto.howstuffworks.com/question324.htm
this link is very helpful.