2007-02-18 23:37:21 · 14 answers · asked by Frank W 1 in Cars & Transportation ➔ Maintenance & Repairs
Do not pull off the batery cable while the engine is running! This worked on older cars(pre computer) but if your car is less than 15 years old you can fry your computer. Any little surge in the electrical system can wreak havoc on these newer cars, be sure not to cross off any wires, if the alternator isn't bad to start with it will be after you short the batery cables, and if you lucky that is all it will mess up.
If it is bad your battery will keep going dead, and if you have an ammeter(in the dash of the car) it will drop, it is usually around 14. Another test using your ammeter(the guage with the battery symbol on it) is to turn on the ignition and look at the reading, then crank the engine, if it doesn't go up then your alternator is most likely dead.
And if you are still unsure, most parts stores will test it for free
Another thing, the belt could be slipping, check the belt, make sure it is tight and not glazed, they don't always squeal whe they are slipping.
2007-02-18 23:55:39 · answer #1 · answered by Anonymous · 2⤊ 0⤋
If your battery light is on it's a good posibility that your alternator is bad. Some suggestions say to remove that battery cable and see if it still runs. Don't do this for it may damage the computer. Most autopart stores will check your charging system free of charge. This is the best way to find out.
2007-02-18 23:49:37 · answer #2 · answered by shawdog 2 · 2⤊ 0⤋
On some cars, with the car running, you can pull the negative battery cable off - if the car continues to run, the alternator is OK - if the car dies, the alternator is bad. With the car running, you can check the voltage at the battery - it should be between 14 and 15 volts (that's the best way to check it). You can get a $15 multimeter and check it or have one of the parts stores like AutoZone or O'Reillys check it for you. They will do this at no charge in hopes of selling some parts. Good luck.
2007-02-19 03:13:39 · answer #3 · answered by Doug R 5 · 0⤊ 2⤋
An easy way to tell if you have a bad alternator is this. (Since all your electronics run off your alternator) When you get your car started, take one of the terminals off your battery. If your car stops running it's your alternator, if it keeps running it's something else.
2007-02-18 23:43:54 · answer #4 · answered by b'ran 1 · 0⤊ 2⤋
This Site Might Help You.
RE:
how do i know if my alternator is bad?
2015-08-06 22:53:30 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Use a Voltmeter set on 20v DC.
Put the wires across the battery terminals with the engine running at a fast idle. You should get artound 14volts, maybe a little less. As you turn on headlights, radio, rear windscreen heater, etc the voltage should not fall.
2007-02-18 23:44:13 · answer #6 · answered by Anonymous · 2⤊ 0⤋
DO NOT ATTEMPT TO REMOVE THE (EITHER) BATTERY CABLE!!! THIs MAY CAUSE SPARKS, THAT CAN CAUSE THE BATTERY TO EXPLODE!! if battery is dead, jump start the vehicle, and take it to Autozone,advance auto parts, o'reilly's,or another Auto supply business, they usually have the ability to test alternators, and batterys, and provide this service free of charge. Good luck!
2007-02-19 01:46:59 · answer #7 · answered by Burts chevy 3 · 3⤊ 0⤋
If you are in the US, take it to Abc auto parts, Autozone or Oreilys, they will check it at no cost to you. If you car starts sometime and sometime it don't you might have a dead cell in your battery. Either way your cost is not going to be great. Good luck.
2007-02-18 23:52:46 · answer #8 · answered by roost2 3 · 2⤊ 0⤋
You'll know it's bad if it does not charge,or does not turn, or makes too much noise.
2007-02-19 01:08:37 · answer #9 · answered by done wrenching 7 · 0⤊ 0⤋
it off if you can or can be driven
take to Advace Auto or Auto Zone and thay will test it for free
2007-02-19 00:15:00 · answer #10 · answered by fish 1 · 0⤊ 0⤋