Skip to comments.Car question - Nissan Sentra
Posted on 07/04/2014 6:52:19 PM PDT by djf
OK, I have a 94 Sentra.
The last four days or so, the brake light and the battery light come on. So I pulled the battery and put the charger to it - nothing!
I went and got a new battery, which took a little bit to put in. The battery WITHOUT the car running has 12.65 volts
Now the first time I started it, almost immediately the battery light came on again, so I quick-like measured it, and it came in with 16 volts. That's high!
So I let it sit for a bit and then start it. While it idles, the battery light stays off. At first, if I give it a slight rev up, the battery light comes back on. Now it seems the light only comes on if I really push the accelerator.
So I am wondering something. If the old battery went total hooters up, then the alternator had to work harder. Does it somehow get "set" at a higher output and take a while to get back to normal?
If not, it's got to be the voltage regulator, which I may be able to get separate. If it just takes a mile or three to reset back to normal output, then I should be ok.
Any experience/ideas are welcome!
BTW, running at idle with the new battery gives about 13.8 volts - totally normal.
Have you checked the fuses and the relays?
Probably bad voltage regulator....
Not sure if I got them all, it has some fusible links, etc.
Most regulators are built into the alternator, even in 94. Know that’s the case for Hondas and Toyotas of the same age.
Are you sure the regulator isn’t built into the alternator?
Oh it is built in. I’m just trying to figure out if it even needs it - yet!
Sounds like a bad voltage regulator.
It’s your alternator which has an internal regulator....if it is the original equipment....it’s almost 20 years old
Time for a new one....
Thankfully it’s a Nissan, if it was a Chevy, you already be on your second or third replacement...
Have you tried turning it off and rebooting it?
It behaves as if the alternator was functioning backwards.
You could have high resistance caused by corrosion in one of the battery cables or terminals. This can cause the regulator to crank out too much voltage and light the lamp.
It could also be caused by a bad or weak diode in the Alternator. Any good parts store can check the Alternator and tell you what if anything is at fault.
I would replace the alternator before it kills another battery.
Very likely, it’s a Windows 8 problem. Always is.
Either that, or it’s Bush’s fault.
The battery was from 2006. So it was due...
Two mornings I went out there and it was deader than a doornail.
If you can get the alternator out, most part stores will test it for free.
Have you checked the blinker fluid?
Well, I put it in, so I should be able to get it out. But if it’s gonna get better, then I don’t need to.
I’ll let it sit for the night.
It’s the voltage regulator and it is almost certainly part of the alternator. Best option is to replace the alternator. I once had a weird problem where my rebuilt alternator would shut-off when it got hot. So if I took it to get a warranty replacement, they would test it, and it would look fine (since it wouldn’t be hot). Drive it for 15 minutes, it cuts out - but they can’t do that on a test stand. So, I figured the best option was to hard-fail it. So I plugged in 120V to the voltage regulator terminals (the smaller wires) for a couple of seconds and nothing happened. Then I ran the alternator on the car and the voltage immediately zoomed up to 16V (just like you)...I had popped the voltage regulator electronics and it no longer regulated. At that point, I took to to the auto store and got my warranty replacement.
In your case, you’re killing your battery with such a high voltage, and also stressing all the electronics in the vehicle - get the new alternator and be done with it.
You’re probably right.
But the thing is I can’t figure out why, with the new battery, the first time I started it the light came on almost immediately - and the voltage tested 16v.
But EVERY TIME I started it since then, it seems to take more and more for the light to come back on. I just drove it to the mailbox and it didn’t come on!
Don’t know...I’ve never understood those lights anyway.
The light is current driven. It lights when it gets power from either the Battery side OR the Alternator side. If the current is balanced(zero) then it is off.
Are you sure you’re logged in?
“The battery was from 2006. So it was due...”
A bad battery can kill an alternator, just like a bad alternator can kill a battery
The circuit that controls the Indicator light is Usually part of the built in Voltage regulator. And it may be that this function is triggered by Conditions other than just under charging. If you are really at 16 volts then it sounds like you are overcharging. You really should replace the Alternator. Don’t buy the cheapest brand sold at the auto store or you may be sorry as they often have a high fail rate. I have had good luck with Duralast from Autozone.
Not suggesting it’s related or a problem, but since you don’t mention it, it’s a fair assumption it needs stated:
I once was in an auto parts store fetching bolts and a guy with a Jeep was having some issues. While I was there, the staff swapped out 3 different batteries...NONE would kick over his starter. They then blamed the starter and were looking it up to price it. I pulled him aside and asked him if he wanted to save some cash and trouble, as I heard/saw what the Jeep was doing when the last 2 batteries were clamped down and he turned the key. He said ‘yes’. I popped off each cable from the battery scored the inside of the clamp with my key, pressed it on hand tight and had him turn the key: Started right up. Bottom line: Corrosion is a dielectric (insulator). That goes for lead terminals, Weatherpack connectors and grounds.
What I’m getting at is you have a 20 year old car; don’t discount connection/ground problems in the process of your troubleshooting (I’m an expert troubleshooter, btw).
And don’t let friends that ‘say’ they know 12V systems modify/wire your car for that hot amp or other accessories...electrical problems that result sometimes are never solved...
Just drove it to the mailbox (about 1/8 mile away) and...
So I got brave... drove it to a local store, about 1 1/2 miles away and...
It’s a Delco alternator that I put in about 2003. Has a lifetime warranty on it, but screw me, I can’t find the paperwork.
I think it’s OK.
Nice...just keep an eye on the voltage.
You might want to get something like this...it can be a lifesaver (or close enough).
Re: your link
Why the hell do they call them cigarette lighters?
I haven’t seen a cigarette lighter in years.
LOL...actually GM, I think, called them Cigar Lighters, as they are big enough for most cigars. I still have cars old enough to have cigarette lighters - but it takes some work to keep them running.
My 1995 Nissan is on it's third alternator; thankfully, it's the only "mechanical" expense I've had in 19 years. As a result, I buy my Nissan new "presents" every once in a while. :)
Those mid-90 Nissans, they were/are good!
I got 237K on mine. I replaced the half/axles in the front and the struts in the rear. That’s about it! Oh, and the alternator.
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