Warning light still on

I fixed my alternator, and I was checking voltage in the trunk near the battery. I unhooked a wire from battery to a distribution box by accident, and the car shut off. It was a 2ga wire. I put it back on, started the car and had a warning light on the dash saying that I had an engine malfunction and reduced power. I unhooked the battery for 20 minutes and the warning light was still on. Do you know what the problem is?
Experienced mechanics share their insights in answering this question :
I am not sure that there is actually a problem. The warning indicator that was produced by the vehicle was likely in reaction to the wire being unplugged from the power distribution box. When a trouble code is stored it will usually take multiple drive cycles or an OBD2 scanner to reset the light. I would recommend having the warning reset with an OBD2 scan tool and this should resolve your issue. If you are noticing any drivability issues, a certified technician from YourMechanic can diagnose your Warning Light and help pinpoint the fault.

How to Identify and Fix Common car Problems ?

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

Battery Charging System warning light

If this light comes on when you`re driving, it indicates that the battery is not charging. This could be due to a problem with your car`s electrical system and it could have several causes, such as a faulty alternator, faulty battery, bad electrical connection or damaged cabling.

When all your dashboard lights turn on at once, it most commonly indicates an issue with the alternator or the charging system. It is common for all the dash lights to come on with no alternator output; low voltage can cause unusual electrical issues. The alternator should be tested at the time of battery replacement.
However, Android Pie gives you more than just the ability to turn it off. You can also modify the alert to your liking. On the App Info page for System UI, select the text “Battery” instead of the checkbox. Choose “Behavior” to reveal several options to how you can adjust the notifications.
The easiest way to reset a check engine light is to disconnect the negative (black/-) battery cable and hold it to the side for 30 to 60 seconds. This will allow your internal diagnostics systems to reset.
A leading sign of a weak battery is the sudden and spontaneous illumination of multiple warning lights and warning messages in your instrument cluster, possibly accompanied by the non-functionality of various systems including the cruise control, anti-lock brakes, traction control, and more.
The check engine light is usually the most serious and feared warning because of the kind of damage it can signal. This warning often indicates the potential for serious engine damage. When ignored, your vehicle could suffer from a blown head gasket or a seized engine.
It is unsafe to drive with your car battery light on. Issues that activate your car battery light, like a defective battery or faulty alternator, can cause your car to lose power. In these instances, your car won`t operate as it normally would.
Tire Pressure Monitoring System: Your TPMS light (which looks like an exclamation mark over a comb, ringed by parentheses), will light up in yellow if your tires have low pressure. If it appears in red, one or more tires have just deflated rapidly.
If you notice the yellow triangle warning with an exclamation point, it could also mean that your ABS sensor is faulty or there`s an issue with the driveshaft. Light Bulb: If this symbol is lit then one or more external lights are out or experiencing an issue.
Remove the phone charger from the cigarette outlet, turn off unnecessary accessories such as the seat heaters sound system, defrost and keep the engine running until the message disappears. It may take five to thirty minutes for the battery to charge and the message to reset.
If your battery warning light comes on whilst you`re driving, it means that your battery is no longer being charged by the alternator and is running only on its own charge. That means that your car is only running on battery power that will eventually run out, bringing your car to a halt.
If your battery warning light comes on whilst you`re driving, it means that your battery is no longer being charged by the alternator and is running only on its own charge. That means that your car is only running on battery power that will eventually run out, bringing your car to a halt.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

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.

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Brake lights are not working. replaced brake light swtch still no brake lights. the third brake light the connection was melted at
ANSWER : The first thing to do is to repair third brake light and replace the brake light fuse and then see if the third brake lights work and the lower lights start working? If only the 3rd brake light starts working then you may need a further checks on the turn signal flasher or switch could be bad.

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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.

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on a 1970 Lincoln mark iii Interior lights wont turn on and warning lights are very dim and doorlock button makes buzzer go on
ANSWER : Hi there. Although the electrical systems on older vehicles tend to be much simpler in design, in many cases, issues like you’ve described can be very tricky to trace. It could possibly be something as simple as an expose wire creating an electrical short or a faulty relay that is not completing an electrical circuit. I wish we can help you further, but the best advice I can offer is to have one of our mobile mechanics come to your location and complete an electrical problems inspection.

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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.

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in my car battery warning light appearing while driving.so I have replaced both battery and alternater still light is on
ANSWER : As you may yourself have seen, there are many reports of this fault with the Civic, that is a battery or alternator is replaced only to have the warning light fail to extinguish despite checking every conceivable electrical possibility. Your only recourse is to have a certified mechanic go through that exercise with your car and that involves first attempting to "re-set" the light. If the warning light returns, the alternator output has to be carefully measured both loaded and unloaded. All terminal connections have to be verified including all grounds. Fuses have to be checked for integrity (continuity) and the possibility of shorts, in for example dash wiring, has to be checked. To request this repair, simply request an electrical components diagnostic and the responding certified mechanic will seek a resolution to this.

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Warning lights are on and battery is low
ANSWER : It sounds like you very possibly have a failing HV (high voltage) battery, also known as the main hybrid battery. You may be lucky and be just under the limits for the battery warranty, as they were extended to 150,000 miles and 10 years from original vehicle in service date. You should have the warning light diagnosis verified first by a qualified technician, such as one from YourMechanic. This ensures that you go to the dealer with the knowledge you need to make sure your battery is replaced under warranty.

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Car shut down and will not start. Warning lights are on – 2006 Toyota Highlander
ANSWER : Hello. From what you describe, it would appear that your vehicle is having some sort of electrical issues. The "Generator Inverter Performance" warning comes on when the computer detects an issue with the vehicle’s electrical generator inverter. The generator inverter is the component that converts the high current electricity from the vehicle’s hybrid battery into a lower power form of electricity that is useable by the vehicle’s various systems.

The inverter is located in the engine bay, as the silver box on top of the engine. Unfortunately, the inverter is a critical component to the functionality of the hybrid system, and therefore to the operation of the vehicle, and, as a result, needs to be repaired or replaced before the vehicle will run again.

The VSC system warning light comes on when the computer detects an issue with the vehicle’s stability control system. This is usually due to a fault with the wheel speed sensors or the ABS module, though electrical issues can sometimes effect this system as well and cause it to behave erratically. I would start by taking care of the generator inverter issue and going from there.

I recommend having a certified mechanic, such as one from YourMechanic, perform an inspection to determine why the warning lights are on and suggest any needed repairs.

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