My alternator is overcharging to about 14.8-15 volts. Can that cause other warning lights to come on?

My alternator is overcharging to about 14.8-15 volts can that cause other lights to come on,like the ABS sensor ,parking brake light ,and it took away my traction control of.pls help
Experienced mechanics share their insights in answering this question :
Hi. Yes, in a lot of cars when the battery is low or the charging system is malfunctioning, the ABS Light, Brake Light and the Traction Control Light will come on. This happens because these systems must have the correct battery voltage for them to operate properly. These lights coming on is just another indicator that the battery or charging system needs to be checked and fixed so the car will operate properly.

I suggest you have a certified technician, such as from YourMechanic, come to your location to replace your alternator and check your car for any other issues.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

A good alternator should maintain battery voltage between 13.9 and 14.8 volts (14.2 is optimum). Even worst-case, with all accessories turned on, there should be at least 13 volts at the battery.
If the voltmeter reads between 14-15 volts then the battery is normal. But if the battery reads over 15 volts or less than 13 volts, then there might be a problem with the alternator. The alternator is over charging the battery or not giving enough charge to the battery.
To fully charge in reasonable times, alternator output must be 14.2 V to 14.5 V as measured right across the battery posts. Above 14.5 volts charging voltage, batteries have a greatly increased tendency to release excessive acidic vapors, hydrogen gas, and to corrode things around the battery.
The build-up of hydrogen gas from an overcharging alternator causes your battery to swell. This also causes the battery to leak highly flammable liquid electrolyte, which is very dangerous. Please see a specialist right away if you notice this happening.
If your battery has a charge between 12.4V and 12.7V, your battery is fully charged and ready to run. If your voltage is below 12.2V, it needs to be recharged. Take a 30-minute drive on the highway or pick up a charger to bring the voltage back up. If your voltage is higher than 12.9V, the battery is overcharged.
14.5-14.6 is normal voltage while the alternator is running.
The alternator should be replaced if AC voltage of more than 50mV is detected (in some cars as much as 100mV is acceptable).
So, to answer your question, Yes, 15 volts is too high. Most car alternators, that normally recharge your battery after every start, and provide power while the engine is running, are normally voltage regulated to about 13.8 to 14.0 volts.
So, to answer your question, Yes, 15 volts is too high. Most car alternators, that normally recharge your battery after every start, and provide power while the engine is running, are normally voltage regulated to about 13.8 to 14.0 volts.
Any reading above 15.0 volts is too high and indicates the alternator is overcharging. The quick answer is that your car`s alternator charges from 15 volts to 16 volts because of your faulty regulator. That leads to more output voltage and, thus, overcharging.
If your bad alternator is producing too much voltage that could damage an ECU as well as other components. A faulty alternator, especially with a faulty regulator may conduct high voltage, there y blowing out many electricals including ECM/ECU.
At high rates of overcharge a battery will progressively heat up. As it gets hotter it will accept more current, heating up even further. This is called thermal runaway and it can destroy a battery in as little as a few hours.
Measuring your car battery`s voltage can help you determine how charged your battery is. A perfect voltage with the engine running is between 13.7 and 14.7V. With the engine off, it should be 12.6 volts.
With the motor running, the multimeter rating should stay in the 14 to 14.5 volt range. Dropping below 14 means either the battery is weak and unreliable for sustained vehicle operation or the alternator is failing.
Turn the lights, radio, fog lights, fan, and other electronics on, making sure the voltage reading doesn`t go below 13. When you shut off the car, make sure the reading is above 12.6. If any of these readings are off, you likely have an issue with your alternator and may want to visit an auto repair shop.
What voltage is too high for an alternator? For standard passenger vehicle 12v systems, anything avove 14.8v is worrisome. Anything below 13.6v will not adequately charge the battery.
For some alternators, it`s normal to see as low as 13 volts. For some, a constant 13.6 volts is an indication of a problem. For others, it`s normal to see as high as 16 volts for long stretches. Still, it`s perfectly normal for others to see the alternator not charge at all intermittently.
What voltage is too high for an alternator? For standard passenger vehicle 12v systems, anything avove 14.8v is worrisome. Anything below 13.6v will not adequately charge the battery.
If the alternator is working well, your multi-meter should read somewhere in the vicinity of 14 volts (typically 13.8-14.2). If it is reading excessively higher than 14 volts (greater than 15 volts) it is possible that the voltage regulator on your alternator is faulty or going bad.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My alternator is overcharging to about 14.8-15 volts. Can that cause other warning lights to come on?
ANSWER : Hi. Yes, in a lot of cars when the battery is low or the charging system is malfunctioning, the ABS Light, Brake Light and the Traction Control Light will come on. This happens because these systems must have the correct battery voltage for them to operate properly. These lights coming on is just another indicator that the battery or charging system needs to be checked and fixed so the car will operate properly.

I suggest you have a certified technician, such as from YourMechanic, come to your location to replace your alternator and check your car for any other issues.

No dash lights, back right tail light is out, no parking lights. Brake lights work though as does head lights.
ANSWER : Hi there. In many cases, when you have electrical problems like you’re describing, it’s caused by multiple electrical component failure. It’s likely that a few electrical relays are not working; especially if you have systems that utilize the same components (such as your brake light and tail lights). I would recommend having a professional mobile mechanic come to your location to complete an electrical problems inspection first, so they can pinpoint what is damaged and recommend the right repairs.

voltage warning light still coming on 30-45 seconds after car starts.
ANSWER : Nothing should be replaced until you have in hand a definitive diagnostic pinpointing the faulty segment of the car’s electrical system. There may be too much voltage drop in the charging circuit, as well as elsewhere, but start with the charging circuit. The faulty segment could be anywhere, so using the factory wiring diagram you just have to methodically and systematically test the entire charging circuit until the fault is found. It’s laborious but compared to replacing parts that might be perfectly good, properly diagnosing the fault will save you money and time in the end. As far as the engine warning light, at the moment I would fix the issue with the charging system first because that may resolve the check engine light. If it doesn’t, just request a check engine light diagnostic. If you want the charging circuit diagnostic steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a charging circuit diagnostic and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Low coolant light comes on when AC, defrost or heater is on, but only if the car is in gear and stopped, what’s wrong with my car?
ANSWER : First, you want to make sure your cooling system is full. Check the radiator not the coolant jug. And check it when it is cold. If it needs coolant, add some. Of course, I don’t feel this problem is an actual low coolant condition. I would expect to find an electrical failure in the instrument cluster or from a component or wiring harness that is connected to the instrument cluster.

As a technician, I have access to reports from technicians across the country. I could not find any reports of this problem, so diagnosing this will require an experienced tech as this is not a common problem. In addition, this happens at intermittent times making it difficult to recreate. The most challenging part of this diagnosis will be recreating the symptom. I suspect it has something to do with the brake switch circuitry because it only seems to happen when you have your foot on the brake. I would begin my diagnosis there with a wiring diagram and test light in hand. The brake switch, instrument cluster, and environmental controls all interact with each other. Something is crossed either because of a failed module or damaged wiring in a harness.

Aside from making sure the coolant is full, this will not likely leave you on the side of the road. If you take it in to be diagnosed, be prepared for them to spend more time than usual to figure it out. Since it isn’t a key problem, you may need to live with it until it completely fails making it much easier to diagnose. Either way, I do recommend having a certified mechanic diagnose the warning light to make sure there isn’t anything serious going on.

Good luck.

Battery light goes on when I start car then turns off, if I rev engine light comes back until rpms go down. Abs goes comes on/off
ANSWER : Batteries can die due to faults in the charging system so ideally a suspected "faulty" battery should be load tested before a decision is made to condemn it. The only exception to this rule is if the battery is already clearly "old" (greater than 5 years) but even then once you put a new battery in, as a replacement for a "dead" battery, you have to comprehensively check out the charging system. Diagnostic Trouble Code P0460 will result in disruption of the dashboard fuel gauge’s ability to accurately report your tank’s fuel levels. The fuel gauge readings may be erratic, or read somewhere off scale. Vehicles equipped with a low fuel warning light feature may also suffer from erratic low fuel warnings in the event of a code P0460. Unless the P0460 code has been reported alongside other trouble code, all of the vehicle’s essential systems should otherwise function normally. I would recommend that you request a check engine light diagnostic to first resolve the fault causing the P0460 code to set. The check gas cap light warning light could be due a faulty gas cap and/or small leaks in the EVAP system.

My battery warning light comes on and then off again repeatedly.
ANSWER : Hi There,
It sounds like you may have a weak connection or a short somewhere causing the excessive power draw on the electrical system. You may also want to check the voltage regulator to see if it is allowing the alternator to charge at a consistent rate as tested. In the event that it is working intermittently, this may cause the charging of the alternator to become erratic or inconsistent resulting in random power surges as you describe.

What could cause my ESP light and ETC light to come on while driving?
ANSWER : Hi there. I wouldn’t get too worried. It is normal for the ESP and ETC lights to come on when the Check Engine Light (CEL) does. They are Electronic Stability Program and Electronic Traction Control. Both are tied into the ABS system.

If the engine or transmission is not working properly, these systems will be disabled. The lights come on to inform you of this. If the engine is rough at idle, it is misfiring. The engine computer can detect even the slightest misfire. When it does it will set a code and turn on the CEL. The code will remain stored even if the light goes out.

Misfires can damage the catalytic converter. This is why the computer will only allow you to go 40mph. It reduces the power output of the engine to prevent more damage. Have the codes read out for you if you wish. Misfire codes are P0300-P0304.

For the rough idle, you will still need someone to diagnose why it is misfiring. If I were to guess, I would think you have a bad ignition coil. There is one for each cylinder. If you would like to have all of this checked, a certified technician from YourMechanic can come to your car’s location to diagnose the rough idle (as well as any other problems) and can advise you on any suggested or urgent repairs.

Abs light, emergency brake light, steering wheel assist light, engine light, EPC light, traction control light
ANSWER : Hello, thank you for writing in. The vehicle does utilize a lot of the same sensors for these systems. Are there any other codes that are coming up when this code appears? If so you will want to take these into consideration when processing the repair and making a diagnosis. The module may be bad, and replacing it should fix the problem. The lights should turn off once the main computer recognizes the new module and the sensors sync up. If you believe the sensors need to be cleaned you may do so. Do as minimal as possible to make sure you are not damaging the sensor or disrupting the wiring inside. A bad connection would make the lights stay on. With so many lights that are effected by the module being illuminated, the module is likely bad or does not have a connection. Check the connection first and then resort to replacing the unit. For more help with these electrical tests, contact our service department.