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Neither as that may or may not work. Test the alternator with a DC Volt meter. It should read between 13.5 to 15.5 volts with engine running at idle. Or drive it to the nearest auto parts store where they will check it for free in most cases.
Unhooking a battery cable with the engine running is a sure way to damage a computer. There will be a voltage spike when pulling the cable off, which may ruin any electronics onthe car.
What else can I help you with?
I have a 2003 Chevy impala how do i know if i have a bad battery or bad alternator?
To test the alternator if funds are low, let the motor idle and remove the negative battery cable, if the motor dies its probably the alternator.
How do you know if you have a faulty battery or a faulty alternator?
A quick test I've always used is to start the car. Remove the neutral cable from the battery. If the car still runs your alternator is fine.
How do you know the problem is the alternator?
If your car doesnt start, it could be the battery. But if the car starts and you unplug the negative cable and the car turns off, its the alternator.
How do you know when your alternator is going up?
If you can't take off the battery cable while running without the car dieing.
How do you know if the alternator is bad?
TestBefore paying money for a new alternator (which I was about to do today), be sure to have the alternator tested. As many people suggest, Auto Zone, and other parts suppliers, will test it for free. You may have bad connections into your alternator...make sure they are secure and free of corrosion. You might also simply need to tighten the alternator belt. A loose belt will also prevent the alternator from charging the battery. Cable testTry this: With the vehicle running, disconnect the negative cable from the battery. If the vehicle keeps running, the battery could be bad. If the vehicle dies, the alternator is probably bad. Most major auto parts stores can test batteries and alternators. Note - the above answer states that you should disconnect the negative cable from the battery. 'The correct answer is to remove the POSITIVE cable not the NEGATIVE.constantly deadYour battery is there for starting purposes only- once you start the car, the alternator/generator takes over, and runs the cars electrical system (and recharges the battery)- if you start your car and then disconnect the battery, if your alternator is good, the car will keep running. bad alternator and the car will die. note that if your alternator is bad, your car can run off the battery for a while till the battery dies. sure sign of bad alternator = constantly dead battery. Additional Answersstart the car the remove positive battery terminal if car stalls or idle drops really low alternator is badMy battery indicator light came on, but the car would still start and the alternator belt was intact. I tested the alternator with a volt meter and sure enough it was bad.Battery continually going dead. Best thing to do is drive the car to an Auto Parts store and have the alternator load tested.If you do not have a voltage tester bring it to a repair shop and have them test the alternator. Puts out between 13-14 volts. If under 13 it is probably badYou can always start the vehicle and disconnect the battery. If it dies, your alternator is the problem. If not something else might be the problem.start or jump-start the vehicle. Remove jumper cables after it's started. Use a volt meter to find out the voltage at the battery. If it's below 13.5 VDC, the alternator is probably bad. Take it to an auto parts retailer and they'll usually test it for free.
How to know if the alternator is gone in a 98 mercury mystique?
let the car run and then pull the negative battery cable off. if the car stalls, the alternator is bad! do you know where the bank 1 o2 sensor 2 is?
How do you remove the alternator in a 1996 Pontiac Grand Prix?
This is what I need to know. First disconnect the battery (neg first) then disconnect the plug and power cable from the alternator. You need to take the serpentine belt off - get a long socket wrench (like a torque wrench) and a 13mm socket (I think it's 13) attach to the idler pulley ( below the alternator to the right) then turn clockwise to push the pulley down and loosen the belt - remove belt. Take out the bolts that hold the alternator - 3 I think. Install is the reverse, final thing is the battery black cable... good luck - I have replaced mine twice now not as hard as it seems - just the serpentine belt is the hassle.
How do you know which battery cable is positive and which is negative in a car if they're not labelled and not connected to a battery?
Following the cables into the engine compartment. The positive cable will run to the alternator or the starter. The negative cable will just connect to a ground source (engine block, frame, etc.)
Should you disconnect your battery if you know the alternator has gone bad?
Only disconnect it when ready to replace the alternator. The primary function of the battery is to store electricity needed to start the car. Secondarily, it stores electricity for use powering the electrical items on the car when the engine is off. If the alternator is not producing sufficient power to run the engine, the battery takes over. Once the battery is drained of its power, the engine will stop. You can jump-start a car whose alternator is faulty but battery is connected, and the car may run for a short time before the battery dies. If there is no battery, the car will start but not stay running once the jump device or cables are disconnected.
How do you know if it is your alternator or your battery?
I assume your battery is running down. If the alternator is defective the battery will never be charged properly. There are a few ways to diagnose this. Start the engine and with a digital volt meter set to the 20 volt DC scale check the voltage at the battery with the engine running. You should read from 13.5 to 15.5 volts. Any less and the alternator is defective. You can also fully charge the battery and then disconnect the negative cable overnight. If the battery is dead the next morning then the battery has a dead cell and must be replaced. You can also drive the vehicle to a local auto parts store where they will check the charging system. Most will do it for free.
How do you install an alternator on a 1993 mercury topaz?
To install an alternator on a 1993 Mercury Topaz, first disconnect the battery and locate the alternator. Remove the drive belt, unplug the electrical connections, and remove the mounting bolts. Install the new alternator in the reverse order, making sure all connections are secure before reconnecting the battery.
Why might a car not start after installing a new battery?
AnswerWithout buying expensive test equipment, you can test it by replacing the questionable part with a known good part.Answerdid you have the new batt.tested where you bought it?you can get a bad batt.off the shelf i know. starter draging.just went though this myselfEven though its a new battery, it may be the alternator!! the easiest way to check it is to get it started when running, take the negative cable or black cable off of your battery if it stays running your alternator is fine if it dies the alternator is bad!! the alternator helps keep the battery charged and going!!
