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I have a 1998 Nissan Altima. It's been doing OK but of course as it's a 1998 I only paid $400 for I've been smoking out some piddly things to take care of.
I've been having trouble with what I thought was a dead battery because the +/- indicator for the alternator wasn't illuminating, but after a testing they found that in fact the alternator was insufficient. They told me that it was putting out about 12.5V when it's supposed to be putting out 14V if I recall correctly.
Obviously the alternator is an important component, I've already priced it and started asking around for mobile mechanics who can swap it out (it seems to be right on top easy to get to), in the meantime I've tried to keep things OK until they can do that. Apparently it must have SOME abilities still in it because it was mostly doing ok until our temps went from being like 55-33 to like 30-15 (it's now warming back up) and then it was needing a jump everytime, also when I jump-started it to go into town I turned the headlights on to see how it would fare (years ago I had a car with a really bad alternator and when driving it at night the headlights within that frame of time would exhaust the system and you'd have to pull over) and they were still glowing at full-strength a good 15 minutes later, and this was after a jump not after a full recharge. Speaking of which I also got a $20 charger at Atwoods (a hardware/tractor/ranch supply kind of store) and brought the battery inside to warm up overnight and then I charged it up full the next morning (I read that you shouldn't jump or recharge a cold battery).
Questions:
If the alternator needs replacing, why didn't the +/- thing light up? (All the other dashlights illuminate so I don't think it's out.) Is this because it hasn't failed "enough?" (In other words, if I had a gauge, it would be just a bit to the left vs all the way.) Did I have the right idea bringing the battery inside to warm up overnight before charging it back up? Lastly, if the temperatures outside are OK, is it really that bad to use an extension cord and charge it with it still in the car? (The instructions are big on saying not to use an extension cord, but I'd rather leave it in the car.)
Before you jump in replacements...
Did you check alternator belt? This is by far more common issue than alternator itself.
No I didn't think of that, guess I should have my normal garage guy do that. Have him change the oil and do a few checks like that while he's at it.
Besides that I was also posting to make sure that workaround I was doing in the meanwhile was a half decent thing in terms of me having the right idea. The main concern is night when I drive for about 20 minutes with the lights on, I know that will drain it more than the day errands will.
sometimes, actually most of the time, alternators dont die outright, they take their time. in the alternator there is a diode bridge which contains six diodes to turn alternating current into direct current. as these diodes die off, the charging capacity of the alternator drops off. alternator can put out just enough current to keep the battery going, though barely, and still not turn on the no charge indicator light.
The voltage regulator is a pcb in the alternator. It may not be operating properly, causing it not to open when needed to charge the battery. When it totally fails, the dash 'bat' light will come on.
Location: Was Midvalley Oregon; Now Eastside Seattle area
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How old is the battery? A battery shop can do a quick check to confirm a faulty alternator or failing battery.
A rebuilt alternator is pretty cheap, and you could DYI install.
with a discharged battery and bad alternator-regulator, a jump will get you started but won't keep you going.
Take a voltage measurement directly on the output-stud of the alternator to the positive of the battery.....you possibly could have a voltage-drop in the cable that connects your
alternator-positive to the battery positive. Put your DC-voltmeter on the case of the alternator and the negative of the battery, the voltage should be very low, .2-volts or less.
Be very careful and use jumper-wires to do these measurement, you need to have the engine running.
Bravo for the person who suggested checking the alternator-belt, I second that idea!
Yes tonight I drove home from work in it, it's about a 15 mile and 23 minute drive, and I had the headlights on the entire time, and they never dimmed. When I got home and switched off the car I left the lights on and checked them, even then they were still at 100% brightness.
So if the alternator is bad, it's apparently in the very early stages of it?
It makes me feel dumb though because in terms of the one person asking "how is the battery," it's a brand new one, I just changed it Thursday. The one originally in there (I bought the car Tues) had been doing OK but as of that day was acting up and the +/- indicator hadn't come on so I figured it was the battery, and I spent $106 on a new one. I probably didn't even need to, and in fact the old battery was dated Dec 2016 (I gave it in on the exchange) and I didn't have them do the test until Sat two days later when the new one was now acting up. Silly me!
Yes someone locally has a rebuilt alternator for $35 ($45 if you don't give them your old one) I'm probably going to get it in the next few days so I'll already have it when the time comes I DO need to switch it over. (Or maybe when I have the oil changed I'll have the garage check the belts?)
I'd say you want to replace the alternator (once you're sure it's the problem) ASAP.. I wouldn't put it off too terribly long.
A battery that doesn't properly get charged can then 'go bad'.. It's not overly common, but.. If you've just spent the money on a new battery, you want to make sure that you don't have to do it again before you would normally have to.
Dude, or dudette.
KISS. Pop hood open. Squeeze alternator belt firmly with your fingers and try to twist it. If you can twist it so that ribs show up, it's either stretched or has no tension on it.
It's not rocket science, and you somehow keep complicating all this more and more.
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