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George H.
George H., Hyundai Technician
Category: Hyundai
Satisfied Customers: 2026
Experience:  Hyundai Gold certified, ASE Master tech 15+ years
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Hyundai Santa Fe Limited: there, about a month ago, I was

Customer Question

Hi there, about a month ago, I was stranded in my 2007 Santa Fe, it was the alternator and it was replaced. At that time, it was noticed that I still had the original battery. The mechanic said it still held a charge and didnt replace it. Two weeks later, guess what, battery light is on. Had the battery replaced and alternator checked. All seemed to be good. 48hrs later, check engine light is on, back to mechanic and said I now have 5 codes, fuel gauge, brake check, throttle, two others I cant recall. But, when he ran the parameters, said all was functioning within normal limits so I just have to wait until something goes. Ugh,
My question is, could the Battery/alternator electrical surge cause some kind of surge or depletion to cause all these sensors to go off....was working well up until alternator went.
Submitted: 6 months ago.
Category: Hyundai
Expert:  Roy replied 6 months ago.
good afternoon my name is ***** ***** I will assist the battery light coming back on is the issue. there is something going on with the new alternator. this issue may have or is causing the other issues. do you have a voltmeter to do some checks??? Roy
Customer: replied 6 months ago.
please read my question again.
Expert:  Roy replied 6 months ago.
I have read your you want to do some tests to find out why this is happening???
Customer: replied 6 months ago.
Ok, as I had stated earlier, the alternator went. Battery wasn't replaced at that time. Original battery. Two weeks later, battery light came on. Had that replaced and alternator checked again. Appeared to be ok. 48 hours later, ENGINE light came on. Took it back to mechanic and gave me 5 different codes.
Could the electrical disturbance from Battery/alternator cause all these sensors to go off? Was running fine before alternator went
Expert:  Roy replied 6 months ago.
and as I stated in my reply, yes, it can. the battery light indicates there is an issue with the alternator. that issue can cause the check engine light to come on. before assuming anything is wrong with sensors, I could use the actual codes or do the voltage tests I am trying to get you to do. Roy
Customer: replied 6 months ago.
The battery light came on, replaced the battery...battery light off. Now check engine light is on.
Mechanic said new battery and alternator are fine.
Now it's the sensors.
I don't have access to a voltmeter to test brand new battery .
Customer: replied 6 months ago.
I was also told when replacing the alternator, the battery should be replaced also, especially since it was 9yrs old.
Expert:  Roy replied 6 months ago.
ok, the battery light returning on is not an indication of a battery failure, it is indicating a charging issue. if the voltage is low or it has ac voltage it will cause the engine pcm to set false codes. the chances of several sensors failing together is nill. you would be testing the alternator for proper voltage both ac and dc voltage my answer still stands that you have an issue with the alternator.
Customer: replied 6 months ago.
Ok, I asked specifically to my mechanic to test it because I read that a bad battery can fry a new alternator. He said it was functioning normally. Do I get a second opinion? Do sensors reset if electrical components are adequate?
Customer: replied 6 months ago.
I just feel if they had changed the 9 yr old battery at the same time as the alternator, I wouldn't be having these issues
Expert:  Roy replied 6 months ago.
I agree with you. what happens is that the 9 year old battery was asking the alternator to work harder to keep it charged. that extra work can cause the alternator to overwork and damage the regulator. just putting voltmeter on it to test will not tell you it is ok. the light came on for a reason and that reason needs to be found. if it is not putting out proper voltage, or is leaking ac voltage into the battery, it will set false codes. thats why I am saying what I am saying. I am not doubting you but further testing needs to be done to insure you are not spending money on something that is not wrong. sensors will not burn out from low voltages. they will just ask for help through the check engine light Roy