Battery keeps dying and is corroded. Is it the alternator or the battery?

ANSWER : The corrosion may have an impact on how well the battery connection transfers the charge from the alternator. It is also possible that you may have a faulty alternator or a weak battery that is not able to take a charge. As you may know, the alternator is responsible for charging the battery while the engine runs by generating amperage and recharging the battery while the engine turns the alternator. The voltage regulator is a unit that regulates the charging of the battery by the alternator and maintaining a certain amperage while the engine runs. When the alternator is not working properly, this may result in the battery quickly losing charge and the car losing all power as you have described. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your charging system.

ANSWER : This may be a sign of a failing voltage regulator or potentially a bad grounding problem causing a draw on the system. The voltage regulator is a unit that regulates the charging of the battery by the alternator. Often times this will result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. In either case, I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.

ANSWER : There are three possibilities, to start with: 1) there is a voltage drop in the wiring between the alternator and the battery; 2) the "parasitic" power draw occurs while the car is running, not so much while it is off, thus overwhelming the alternator and consequently the battery is not being fully re-charged; 3) there is a parasitic power draw when the car is off but to pick it up requires data logging. With regard to these possibilities, if you desire that the required diagnostic steps be performed by a certified mechanic, please simply request an electrical circuit/charging system diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : Hello. If the battery and alternator are fine then I would test the ignition switch. It will commonly stay on and cause this. If it is fine, then an amperage draw test needs to be done on the vehicle. If all of the electronics are stock, then the issue may be a sticking relay. I have had the main fuse box fail internally and cause this a few times on this vehicle and the amperage draw test will identify this as the issue. If you need to have this looked at, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose your battery.

ANSWER : Hello. If your charge indicator is on, this indicates a problem in the system. The charge indicator will have a resistor that is about 390 ohms when tested and if it is bad then may cause light to come on. You are having a possible charge problem with alternator. A junk yard alternator may be bad and you would not know it until it is installed. You should have the complete charging system diagnosed by a qualified mechanic that will be able to go over the entire circuit.

ANSWER : This is likely a sign of a failing voltage regulator. This is a unit that regulates the charging of the battery by the alternator. In your case, it sounds like the voltage output from the alternator may be much too high resulting in overcharging the battery and burning up wires in the process. I would recommend having an expert from YourMechanic come to your location to diagnose and properly test your vehicle’s charging system.

ANSWER : Hi there. The best way to diagnose why a battery would constantly drain is to review it’s job and how it is recharged. The battery is responsible for powering all electrical systems until the vehicle is started. At this point, the alternator takes over and also continually charges the battery while the vehicle is in use. A battery will drain when one of two things occurs. First, a battery will drain if it is constantly in use; supplying power to an electrical component even if the key is not in the ignition. Second, the battery will eventually die if the battery is not being charged frequently. However, since this is happening every two days, my initial thought would be that some electrical component on your 86 Olds is continuing to draw power from the battery. This is known as a parasitic drain. The best way to determine the source of this battery issue is to have one of our professional mobile mechanics come to your location and complete a battery will not hold a charge inspection.

ANSWER : The battery should be load tested. Simply charging the battery or measuring voltage is not adequate. Measure charging output, too. You want to confirm that the ignition system, including for instance the ignition coil and ignition switch, are not intermittently cutting out. Coils can fail as temperature rises (resistance increases with temperature) so if you run the car for a while and all of a sudden it quits, measure the resistance of the coil windings to see if that provides a clue. Apart from that, the ENTIRE primary side ignition circuit has to be checked, using voltage drop testing (and testing of the hall effect sensor in the distributor), to rule the primary side in or out. If you want the required diagnostic steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a stalling 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.