Battery voltage ISSUE 14-20 Silverado/Sierra

[@U2NOZ]

All HERO's don't wear capes!!! Thanks bruh!!!

[@sydneyburns676]

as you explained how it charged it would of been nice to see you start it to show everyone that it does work that way. GREAT video

[@assyrianbetnahrian9574]

What was the problem..I didn't understand shit from this guy just showing the dash without running the track...what was he fixing...we know that's normal on new or old tracks ...the truck is not smart that's just the design of it

[@hounddoggzgaming6970]

My truck does the same but my battery went out. I was scared so i bought a new one and works just fine. Im glad i found this video i was about to buy a alternator

[@Lito_-we4xy]

Recently noticed this also on my '16 Silverado and was worried something was wrong with the alternator or battery. Only had it for a few months so still getting used to it. Thanks for the vid

[@chrissikora8228]

Same got a 18 model

[@otheroddities]

My 2015 Silverado with 4.3 Does that after running for several minutes, after running few errand don't see it move. I recently bought this truck used had it for a week replaced battery and alternator

[@msvfamily2023]

Thank you. Brother! Just got the truck a month ago, and I took a trip from Miami to North Carolina. And on my way back saw my battery gaged was going down and I had 7 hours left till get home. Thank you brother again!!

[@greyowloutdoors4817]

Hey everyone i figured out a solution that’s free and it works. Voltage will never go down below 13.9 when truck is running. I got a 2017 Silverado 5.3 Ecotec. I have been having the same issue with voltage drop. I do run an amplifier for my subwoofers so it was hurting my amplifier a lot with the voltage drop. Even with 3 kinetik 2400 AGM batteries it would still go down to low 12s volts but Here is the trick to fix it. It takes 2 seconds to do it. And I mean 2 seconds. When you start your truck. Turn your lights on and the voltage will stay at 14.0. The whole time as long as the truck is started. Turn off headlights and u will see it drop immediately. Works for me. Hope this helps guys and gals.

[@edgarnevarez7554]

Literally almost bought an alternator 😂 thanks dude! Mine fluctuates. Doesn’t do it all the time. Saw it a few days ago, and today again but it went back up after about 5 mins of driving.

[@OG-ht7vl]

mine too brotha

[@arsena7538]

Excellent work man. Simple and to the point. I was trying to help a coworker figure this out and you answered his question. I actually learned something new as well about the computer regulated charging.

[@redwhiteblue7831]

Thank you, just put a new battery in yesterday. Never seen it there until now. Thanks again. 👍

[@eightyninetreasure]

Thank goodness. Been driving my husbands truck for the last few weeks and recently saw the fluctuation on the dashboard. My stomach dropped and wondered wtf. Glad I found this video quickly on YT. Thanks bro.

[@robertblalock4074]

Sometimes this fluctuation can be caused by resistance in your battery cables. If the resistance gets too bad you will have electrical issues to your computer components. I had this problem with my 2016 Chevy suburban. My steering module kept losing communication which would cause loss of power steering. Which is electrically assisted. I would also lose infocenter and some dash nerd lights would come on and then back off. There is a tsp about this issue. So if you have some funky issues besides voltage being up and down I suggest looking into resistance on your battery cables.

[@jacobjordan9514]

I have a 2018 silverado and it just started doing this today.

[@Fox250R]

@@jacobjordan9514 did you do anything About it yet?

[@joeroe2839]

What was the solution this just happened to my parents suburban??!

[@robertblalock4074]

@@joeroe2839 the solution for my suburban was to replace the positive battery cables that are infused into the fuse box. So the fuse box was actually replaced too. Looking at my post it was 8 months ago. I've had zero issues since.

[@robertblalock4074]

I took my truck to the dealership to have this done. There is a technical service bulletin about this issue. So Chevy should definitely know.

[@Coalblack79k10]

Still helping people thanks I noticed my 18 yukon go a little above 14 and then other times down to 12 it makes sense now Appreciate it 👍

[@trooperhank]

Sweet, mine looked just like that. Was showing 12.1v and dropping using a scanner. Actually killed a battery while idling. I'm so glad people post this with no actual operating data given. Really helpful when you try to get troubleshooting help and everyone says "Its normal, check out his video!!!!!!" But now I know my truck is totally good, thanks!!!

[@damianbenjamin8352]

I recently just noticed this on my truck. And instantly thought “crap my battery is going” glad I just happened to stumble upon this vid!

[@fukubish6024]

I just installed a new alternator and battery . Truck works like a charm now . Haven’t had any issues with low voltage

[@jamesallen5250]

Thank you, first video I found researching this. Just recently bought my 2018 1500 LT and was a little concerned but not anymore.

[@SuperGmann10]

Well, hell, I wish I'd seen this about a week ago! Just bought a Seirra that is pretty much doing exactly this. Replaced the alternator. Same thing. Took it to a shop who said they couldn't find a problem. Took it to another shop today who is going to check it out tomorrow! This video would have probably saved me some money and aggravation!

[@lyonanddebanderson4418]

Thank you for this post, Ignore the haters. I have a 2014 high country 6.2L 1500 Silverado, finally actually read the manual-states in there that there will be fluctuation in the charging system.

[@ernestcrist2930]

Never noticed until my battery died and left me stranded. Swapped the battery and it lasted a week and it was dead again. Ended up having a bad voltage regulator and had to replace my alternator. Now it fluctuates like that. How are you supposed to know the difference between “doing what it’s supposed to do” and an actual problem.

[@faded3657]

right, this didnt help me at all lol it's definitely the regulator

[@markcrawford9693]

My 2016 silverado did the same thing until I put in a AGM battery, now it stay at 14

[@donoosterbaan2288]

BS mine ran straight up at 14 volts at all times. 36,000 miles. Now it runs straight up for a while and then drops down to like you show on your video. Alternator is getting replaced

[@roderickr35]

I have to AGM, mine did that until I added a 4awg ground on the passenger side thru the BMS sensor,stays at 14.4 and when charged drops to 13.9

[@JavierElectronico]

@@donoosterbaan2288 was it? The alternator?

[@alfrecu]

That’s exactly how it works, I bought my 2020 Silverado about 4 months ago and I always saw the charging level at 14 and above, so to me it was the way should be, my truck had the old battery, I realized that the battery was going bad when failed starting the truck, so I bought and installed a new one, the GM manufacturer recommended. Guess what happened, I’m driving and starting to see that volt fluctuating, I thought my alternator was going bad. It scared me…. Checked the manual and right there it tells you that is normal and it will fluctuate from low charge to high charge, of course the reason before was always at 14 because the battery was bad. So my people don’t freak out, it’s normal!

[@josecamacho7234]

This applies to 2016 too?

[@alfrecu]

@@josecamacho7234 In 2016 he had people, high ranked and very good and ethical staff who tried to keep him on following the constitution, that’s why most his closest staff don’t support him any longer and believe he’s a dangerous person to America, this time along with the the shameless decision of the Supreme Court giving a president full immunity is not going to happen, as he said he would like to have the military, the judicial and legislative to do his will…. Anything more closer to a dictatorship, but don’t take from me or his 40 plus close staffers…..just listen to what he said

[@jimrodmrt1]

I just bought a 2021 Silverado, Saturday, and I noticed the voltage grop this morning... I was like wtf.... thanks for clearing that up

[@averagejoe6150]

For everyone who owns these trucks, including myself, Chevy has dubbed this the RVC (Regulated Voltage Control) or something like that. I works by passing all of the grounds off of the battery through a battery current sensor. One thing that SUCKS about this is that if you're into car audio, like I am, you find out pretty quickly that this makes a big 3 upgrade almost impossible to do properly without adversely effecting your operating system. The battery current sensor is what tells your alternator "Hey, time to clock in, need some juice." If you pass ANY of your grounds outside of the current sensor it won't read properly, thus negatively effecting your batteries and alternator life span. The system is great except for that alone. And I have searched, and searched, and searched, and gave up, and then searched, and searched, and searched. You cannot find a larger aftermarket variant that will allow you pass 0 gauge wire through it and still be able to fit the other grounds.

[@2009mechanic]

THIS is exactly what I saw on my 2018 silverado. Dealer checked out and report was " it is operating within the factory specifications". They never at any time told me the charging system algorythm in the computer is what is telling it to do that and IS NORMAL. I have noticed that since I added the second battery under the hood behind the Left headlamp that the voltage runs just a tiny bit higher on the gauge than when it was only charging ONE BATTERY. I run big power winches on my trailers and on the truck when needed. You need a second battery to do that or it will destroy the alternator and other things in the electrical system. I also pull a 5th wheel camper toy hauler with 3 coach batteries to keep charged. So that is a total of 5 batteries to keep topped off while driving. Never had an issue . Never had to upsize the alternator either. The trick was starting out with fully charged coach batteries to begin with.

[@2009mechanic]

This never happened on my 2008 Sierra.

[@jgeistdo]

Thanks I just got my Silverado and was searching this very issue that come to find out isn’t an issue I appreciate this

[@HB-zk7ms]

First noticed this on my 2015 Doublecab driving back from Arizona. Called the dealer and they said what you said. Thanks for the content

[@lhamilalhamy9027]

Am so glad you did the video, thank you so much for the clear and to the point explanation. I watched many videos and finally yours answered my question. Talking about stuff but showing the simple thing is useful a specially for one who is not familiar with it and having to deal with as a beginner. Thank you again 👌

[@adamturner7399]

And now I feel like an idiot, thank you for the awesome video!

[@dboyd1124]

Thanks 4 the info. Just bought a 2020 Silverado 2 months ago. An notice tht voltage move was wondering.

[@AltruisticWarrior]

Mine fluctuates rapidly but we run a lot of equipment like a police light bar etc. That said, if you turn on tow/haul mode or the headlights, it should increase the voltage output and keep it at a higher level. This is a rather old feature in GM vehicles to save a small amount of fuel by throttling the alternator output.

[@zachbailey7148]

Big time help! Except I was 2 hours out on a 6 hour trip home my gauge started doing this. Scared the hell out of me so I turned around went to Napa and installed a new battery in their parking lot. Feel pretty dumb now😂

[@yaseenjudeh7991]

I did the same 😂😂

[@Hidden-comment164]

Did the new battery do the fluctuating too?

[@weethee2351]

Mine does the same thing. Been doing it since I got it. Never had an issue. Always starts

[@edwardwelton6133]

Thanks for the info, definitely answered all my questions

[@joelstevenson5458]

Mine started doing it this weekend and freaked me thank you for the video

[@OG-ht7vl]

me too

[@cassidyg3131]

Really appreciate the video had the same issues with my truck

[@APEXERIK]

I recently had this problem with my truck thanks for the peace of mind

[@danielturner3891]

Is the oil supposed to do that as well because mine does that in my 2015 chevrolet Silverado 1500 lt

[@markdavid4897]

Once the engine is warmed, the oil pressure will increase or decrease with engine speed. As long as you have at least 10 psi of pressure for every 1,000 rpm on the tachometer, you are OK. Less than that the bearing clearances (main bearings) have probably increased due to wear, or the oil pump is wearing more, or a combination of both, but fluctuation as the engine miles and age increase are pretty normal. One way to increase the operating oil pressure a little is by switching to a slightly higher oil weight (first number, 5W-30 vs 10W-30, or even 15W-40 in some cases). The new selected wt. has to be acceptable in your Owner's manual chart for oil viscosities vs outside operating temperatures. With an increase in oil weight, your mpg might go down a bit, but protecting the engine outweighs the small mpg change, IMO.

[@danielturner3891]

Thank you very much for this information is good to know this is my first Chevy 15 I just wanted to make sure it's kind of worried me a little bit

[@james061962jb]

Thanks for the info i just 2014 silverdao it done today altenator checked good thanks

[@bossdaddy348]

Thank you very much.you saved me alot of stress.i bought a new to me 2016 sierra and it does this

[@philshock3805]

Not sure if this true in all cases. I just replaced the battery in my 2014 a few days ago and everything seemed fine. However, during a short run into town an hour ago, I noticed my gauge hanging out on the low end of your "acceptable range". (I looked because the window seemed to struggle going up) Turned the truck off at the destination and restarted .... 14+ volts so I figured it was a fluke. Coming back home, again it started out at 14 volts but quickly dropped to 9-11 volts within a minute or two of driving. In the 9+ years I've owned this truck, I've NEVER noticed my gauge anywhere except 14+ volts. I'm thinking this new battery is bad but not sure.

[@Owneddd1]

If you're voltage spikes in these trucks it can cause the TCM to fail. It's happened to 3 different 2500hd pickups I've owned.

[@damonjones4597]

I have a 2016 Serria and my tcm failed so I had it replaced and now my voltage is spiking.

[@gerrydt57]

Took the fear right out of me thanks Brother

[@eddieotakara6938]

Thanks! I just noticed this on my 21 Sierra and I was worried Very helpful!

[@jonathanavila9699]

Mine literally kicked back up while I was watching this. Thanks for this video

[@ES44AC-2]

Good video. All vehicles allow the battery voltage to fluctuate and some of the gauges are just inaccurate themselves. Got a Ford work truck that has a fictitious volt meter, probably sourced from China. The Alternator and battery are fine.

[@KM-nq8hy]

Mine just started doing this. I have a 2015 Silverado. My first 4 years of having the truck it never did this. I replaced the battery in 2019. It died one day and I replaced it. I noticed after I replaced it the voltage dipped down while on a 30 minute trip. I replaced the alternator and it ran a tad high for about a week and now it’s doing this fluctuation… I hope it’s nothing

[@hectortrevino758]

Same here, just added a battery and new alt. Did the same when i was going out town. Freak out and had too grab my other truck.

[@dmalin7042]

What was the issue?

[@bryanfromzion]

Same here what was the issue?

[@LOVESHREVEPORTBOSSIER]

Thank you so much for this.. My 2015 Suburban drops to around 12-13 volts when driving with no headlights. If I turn my headlights on it runs right in the middle until I turn my A/C on and then it drops back to 12-13 when idle, will jump back to the middle while driving. I’ve had mechanics tell me my alternator voltage regulator was bad but my truck always cranks right up. Thank you for this video, I just bought this truck a few months ago and never seen voltage jump up and down like that.

[@kelaro75]

It's because of the voltage regulator on these trucks.

[@nicholasowens5058]

Mine is doing this and alternator and battery are fine but started just clicking when I go to start it a few times before it starts so I’m not sure,checked for loose connection and so far can’t find anything

[@1GomezE]

hi ive had chevy for over 20 years currently 2014 one thing I noticed lights dim when I roll down windows . to fix that I added a second battery now its not an issue. now I have gained 10% miles per gallon and my gauge is always on 14 or above . I would recommend a second battery since I feel its not enough to just have one try it and call my bullshit if I'm wrong but its a big difference with lighting and performance

[@BEASTMODE988]

Been having same issue I plan on adding a second battery now thanks

[@fma4396]

My work truck does the same thing except I also get the Red battery light with a read out on the center display saying that the battery/charging system needs serviced and I also have times when it won't start,it won't engage or starter drags. Both the battery and alternator have been changed and has same issues

[@petejimenez4321]

I really appreciate this video and your input, thank you!

[@stevemorford2246]

The problem occurs when the "smart" alternator does not adequately charge the battery. Multiple starts in a short period leave the battery drained & the engine barely turns over making starting a challenge. I've found loosening the terminals, cleaning them & retightening solves this problem.

[@Jgamez.47]

I know you posted this video years ago but I’m having trouble with my 2018 Silverado lt , would low battery voltage cause it to stall out by idling while in park ?

[@johnymartinez3804]

Yea had the same problem

[@BillVrouhas]

I have been working on this problem all summer and I found out that mine was the fuses on top of the battery 135 dollars at the dealer in NH best money I spent all summer

[@Mistah_J_786]

Mine does the same thing. I’m not going to lie I did get alil worried being this is my first truck I’ve ever owned lol. Thanks for clarifying

[@DeanVincent46]

Hi great info! Did this thought apply while the truck is on too??

[@jonnysnipes3123]

i hate that feature because if the alternator was really taking a dump i would have just assumed it was just the feature kicking in and then id be at a stop light when the truck stops running

[@KNIGHTJUMPS]

Is this fine? Cus' I need to confirm if it's fine. If It is fine that's great but if it's not fine, not so great. So it's fine right? Jus' tryna' fine out. Thanks.

[@OG-ht7vl]

is your truck still doing that?

[@bimmerguy5785]

🇨🇦 Thanks for this information I just bought a 2017 GMC a couple of weeks ago and noticed that, I was about to go back to dealership. Just noticed that my domestic GMC is built in Mexico and my wifes Import X5 is built in South Carolina? What is going on here?🇨🇦

[@JayBeezy31]

Get to it brother…. We get it bro ahhh there you go I gotta listen now thanks in advance

[@adrianmartinez3220]

Mine is always lower than 14 and my dashboard brightness will fluctuate from dim to bright all on its own.. any idea what it might be?

[@jrich8629]

My 2018 Silverado does the same thing but recently it’s starting to also say service the charging system when it dips down. Then around 30 seconds or less later the voltage goes back to at or above 14 and the service message goes away. That service message popping up doesn’t seem normal to me.

[@ryanmoore9374]

What ended up happening?

[@christianbroussard9962]

Following! Having same issue

[@jasonkarls2384]

Same thing for me, the issue occurs when it is running, voltage is often low, not just at the start. And I had a new battery put in, and it still does the same thing.

[@Fox250R]

@@jasonkarls2384 I put a new battery in my 18 and yes it’s still does the same crap. I wonder if doing the big 3 would help ?

[@Amanda_C48]

A little off topic, but are you still using range technology? If so, anymore issues?

[@Rusty3003]

What issues was the Range plug in causing?

[@codygilmore74]

I just replaced my battery on my 2015 and it started doing this. Why did it never move from 14 the first 5 years I had it?

[@leksterbs]

I got a 2016 suburban have the same issue when it’s running is that normal?

[@joel.3112]

Yes its completely normal, same thing my Suburban and Tahoe are doing.

[@sirgilbert605]

My 07 chevy classic does the same thing, looks identical to that. Start it up in the morning and it's right at 14. 20 mins down the road and it's at 12.6. But it makes sense though what you're saying!!

[@lazyboiz8255]

Mine literally just started doing this after i replaced the battery. Had a bad batteryso it went dead. Replaced the alternator, cleaned the main ground wire that's connected on passenger side firewall and that remedied it for a week. I bought my high country brand new in 2018 and it never did this before. It had gobe through 2 batteries though. It now drops so low that my "battery charging system" warning light cones on then goes off. I'm lost.

[@ashleighsherlin4704]

My gmc 2018 Sierra just got new alternator and battery it never moved until i got those two thing changed. Why would that be ?

[@michaelcreech6509]

Had me replace all 4 nothing thk u BRO❤🎉

[@72eparsons]

Ok my 2014 just started doing this a couple of months ago. Before this it stayed at 14 volts and barely moved. I replaced the battery, alternator twice, complete negative cable harness, cleaned all the grounds and the whole positive unit on top of the battery. If I put my truck in park while running the battery charge service comes on and the battery light. Give it a little gas and it goes off. The frustration has me almost willing to get a payment again.

[@ctjsimmons]

Bad connection somewhere. Rather a terminal with oxidation or corrosion. Sometimes oxidation is hard to notice. Or maybe a poor ground to frame or missing ground from body (not frame). Or bad cell in battery. The fact you rev and it gets better means more charge and more amps available.. if alternator and battery are good , it’s working or terminals

[@juancamaney7700]

Just happened to me on a 2015 sierra, and about to get a new alternator, thanks

[@bbenton1996]

🤦🏼‍♂️ how do people think the battery and charging system work

[@aaronheneghan1693]

I noticed this on my 2012 silverado and not used to that. So it's pretty normal for most of the newer chevys?

[@fz10rider47]

I added LED headlights a couple of months ago and they worked fine. All of a sudden, when they come on, they will start flickering after a couple of minutes and totally go out. I can switch from Auto to on and they come back on and do the same thing after a couple of minutes. I had my battery checked and it is reading good. They checked the alternator output and it was reading 15.6. They said my voltage regulator is bad and that is why the LEDs go off. Is this true?

[@theheadlightpros]

your truck requires canbus leds to run them on it, try a different brand or canbus decoders

[@denniswestjr443]

What about your temperature gauge stops working and the fans kick on high i replaced the battery and that fixed it until it done it again

[@airamee103006]

My 2017 goes down that low after putting in drive and going now it sits there dont get no lower is that bad or is it what you explaining here

[@swamx737]

Just replaced my battery. I saw it today while I was driving voltage was just above 12. Got home, shut the truck off, started it back and it read 14. I tested the alternator before I changed batteries, and it read good so I’m going to assume this is normal…. Even though I have never noticed this before. I’ve had this 2018 gmc Sierra for about a year now

[@donaldjackson4456]

Mine stays at 13.4 running. Im going crazy trying to fix it. Replaced battery and alternator. Still does the same thing I don’t know what else to do

[@johnnysanchez-ld7bg]

did you ever ended up fixing the issue?

[@robertnewell897]

I just got a ceavy my voltage meter does that thanks for the info on video

[@leealberts9590]

I Changed Alternator Before I found out about this system! Woulda been nice to know about this before I spent $200 on an alternator!

[@kaidenreynolds2822]

I thought it was the alternator as well. Now I feel like dumbass after spending $370.00 on a new alternator 🤦

[@leealberts9590]

@@kaidenreynolds2822 I think GM Ford or whoever uses this type of system should inform the buyer before we run into this sorta situation

[@moonshinerandy609]

Thanks man it was scaring the shit out of me

[@truettnelson9802]

Parking is a different story but what if you driving the truck and notice the gauge drops here and there?..

[@melvinjones7769]

hello friends, I have a 2014 silverado, today it appeared "active battery saving" but the needle shows me "14", is it normal?

[@danielmcginnis6630]

I have a 2019 high country you know anything about the idle? I feel like it idles extremely lower than what I’m use to seeing, is this normal?

[@morganfelix1380]

I have 2 brandnew YellowTop Optima batteries wired parallel and and higher voltage brand new alternator, since installing I have been having this problem! N e suggestions? Maybe new sensor?

[@andrewrehnert4997]

Why would a brand new battery not start the truck if this is normal?

[@steelreaper5653]

Mine does it while running it stays about 12volts then kicks in for about 5 minutes then goes back down 5 hour road trip still going strong

[@otheroddities]

My 2015 Silverado with 4.3 Does that after running for several minutes, after running few errand don't see it move. I recently bought this truck used had it for a week replaced battery and alternator

[@ihian82]

Love the vids man. You ever thought about putting baby squat on a dyno to see what your making hp and for torque?

[@lmfscrew]

It’s basically stock with heavy wheels, numbers would be terrible lol would be fun though

[@rscarlberg]

Mine has started to drop below the low end mark, lights get dim and bright and now I'm getting a charging system message. 2015 Silverado LTZ

[@arturo2637]

Is it normal for the battery gauge to drop to under the 14 while driving then go up to 14

[@apostolicway2604]

1:47 But did it do this the first year or two truck was bought new?

[@youngtapo253]

Do you know anything about the LED bar underneath that tailgate

[@robertrandin9568]

My 2018 Chevy Silverado does it even when I'm running sometimes in the morning it's way up over 14 but through the day while I'm driving it does go down a little under 14 is this normal while it's running cuz you said while it's off

[@Fox250R]

It’s not normal but they say it is

[@fike301]

Im pretty sure my 2006 z71 Silverado was same way....definitely 2018 Silverado also same, amazing how long it takes some to notice guage readings? I have also noticed the 18s with the louvers/window blinds( apperantly they open and close) in front of the radiator the temp guages fluctuates more tha older models....notice when towing boat and WOT uphills . I laugh at GM using this because this was common on old Mack trucks back in the 70s

[@joseaguirre1014]

I just replaced the battery and it stays slightly above 9 even when I am driving. It jumps to 14 when I first start it. 2016 Silverado 1500

[@Fox250R]

My 18 does the same crap. I run ham radios and the lower voltage is messing with my transmit. I wish I could just disconnect it some how. I wonder if the big 3 would help ?

[@Fox250R]

It’s not normal no matter what anyone tells you

[@airamee103006]

Did it continue doing this i just replaced my battery last week. And now i have this happening

[@joseaguirre1014]

@@airamee103006 No, it slowly went away. It took like 2 months, I searched for answers all over the internet and the best was that it only jumps to 14 or slightly above when it need to charge and in a new battery it does not need to charge as much. The battery is working, no problem for over one year

[@eastcoastkickz4891]

Make sure you get the right alternator . My car came with a 170 amp Autozone gave me a 150

[@bryanbeam]

For 5 years my guage never came off of the 14v mark. Now today it dropped to 13.something for about 120 miles then on my way home 180 miles it was stuck on 14v again. And when i was coming home it was dark and lights were running.

[@jakeromero5937]

Was your charging system indicator on?

[@whos_kevv3632]

So does it show when you get the alternator that it is over charging the battery but it says battery is fine and alternator is fine