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Bubba James 04-02-2014 08:23 AM

Possible alternator problems?
So I've noticed this little issue for a couple weeks now. My headlights "flicker" almost, on certain days. Especially under heavy electrical load at a stop. (Rear defroster, ac condenser on) The flicker or dimming happens when I engage a turn signal, or anything of the sort as well as just normal driving. The other night while in a drive-through, the radio even turned off for a second due to lost power. Could this be my alt. getting ready to crap the bed? Is there a way to test it without ripping it out? Anyone ever had this problem?

brfatal 04-02-2014 12:02 PM

Advance Auto does a free test. I think Autozone may as well.

arcticscythe 04-02-2014 12:44 PM

While your at the shop have them test your battery as well. It sounds alot like an alternator issue but if your alternator is going bad that puts alot of stress on your battery, it may be worth money to drop in a new battery at the same time.

Brockton 04-02-2014 01:23 PM

Autozone can test it. Just bring your car there, they will hook it up and test the battery, then starter, then alternate all in a few minutes and tell you what's going on with those systems.

Bubba James 04-02-2014 01:24 PM


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Bubba James 04-22-2014 03:00 PM

Ok had my batt and alt tested. Alt was fine but batt at 1/4 life left. Today whilst driving home, car bucked (like when you turn on the a/c) and the abs light came on for a sec. Which points to loss/reduction of power. Does the electrical system pull power from the batt or alt? Would a weak batt cause this?

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p51302 08-19-2014 03:58 AM

I have had similar issues with numerous cars over the years. I have had it go both ways, bad battery and bad alternator.

The battery is used to start the car.

The alternator is used to run the car and charge the battery after the engine is running.

I know from experience that a battery with a bad cell can cause the weirdest electrical system problems and could take out an alternator. So, if you have a battery that won't hold a charge or dissipates it charge quickly, replace it.

My weirdness issue I ever had is that AutoZone tested my alternator and it passed, but at times when driving, it would not produce voltage and my car was actually be running by the battery alone. I'm not putting down AutoZone in anyway. It was an intermittent alternator issue.

So, what I had to do is carry a voltmeter in my car waiting for this occurrence to happen. If the lights would dim, I immediately pulled over and kept the car running. I then tested the voltage across the battery. It needs to be around 14.1 - 14.7. If not, you got it, bad alternator.

IMHO, you either just have an old battery or your alternator could intermittently be failing. Why do I say that? Alternator tested fine, yet your battery has a 1/4 of the CCA it should, meaning a weak battery. So, if your battery is old, than it is probably just your battery. If fairly new, than I would guess your alternator is bad or you have a bad ground.

Are you charging your battery tonight? If so, ensure it can accept a full charge and that after starting your car a several times, it doesn't loose a significant portion of its stored voltage. For example, after the charge, it's voltage should around 12.5 volts. If you start the car three times and shut it off right after it starts. After waiting a few minutes, measure your sitting battery voltage across your battery. If it has decreased below 12 volts or so, it's a bad battery.

Sorry for the long response, but I hope it helps you out.

Epictofer 08-19-2014 10:50 AM

replace battery first as p51302 said, it can cause some crazy stuff to happen if it is weak. I was also going to suggest checking grounds as well. a loose ground could cause the flickering and dimming of lights so thats something else that you should check. As i see it we know the battery is bad, and you need one anyhow. i would try that first and if it doesnt fix that particular problem you still needed the battery anyway so it doesnt sting so bad.

Bubba James 08-20-2014 02:27 PM

Well, still to this day it does it. Voktahe will drop to as low as 10, and as high as 17. It's a "Tough One" brand, which I have heard no good things about and even watched a YouTube vid of one failing right out if the box.

arcticscythe 08-20-2014 03:15 PM

Bubba James, It might be worth investing in one of those cigarette lighter voltage displays, Just to keep an eye on things. If you seeeing voltage swings as high as 17 you definitly have something weird going on. Grab a name brand battery from your local big box store first and give that a try. If it keeps jumping from 10 to 17 volts then something is definitely up. If the battery and alternator test normally you might be having a vehicle ground issue. If your grounding straps are not making good connections you could be getting surges of power from the alternator. Replacing grounding straps is super easy and for about $30 you can get nice heavy gauge PVC wrapped wire and eyelets from your local hardware store. I saw a thread a long time ago on nasioc that should help if you decide to DIY a grounding kit. [URL=""][/URL]

Hope that helps

Bubba James 08-21-2014 05:08 AM

Going to try the battery today, I suppose. I'll keep you devils posted.

Epictofer 08-21-2014 06:40 AM

it kinda sounds like the voltage regulator on the back of the alternator is acting crazy....

p51302 08-21-2014 11:16 AM

I didn't realize you had such wide voltage spikes. If it were my car, I would change the battery and alternator.

Bubba James 08-28-2014 03:12 PM

Ok. A little update on the issues at hand. Two "Tough One" (lol) alts had voltage regulators die within a week. Usually when hot, which, in my opinion is indicative of weak/cheap soldering. See it all the time at my job. So, based on a recommendation, i bought an Ultima alt from O'Reilys. Within an hour of use the pulley bearing was shot and smoking. Belt was not too tight. So, I bit the bullet and waited for a Bosch to be delivered. Installed it 2 days ago and haven't had a problem since. Will let you killers know if anything changes.

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