Start the engine, while the engine is running, remove either battery cable. It should stay running, if not, possible bad charging system. Or take it to auto zone. They check them for free
NEVER EVER disconnect a battery cable while the engine is running unless you like your computers fried.
Here's a link to the proper way to test:
Saying again, never ever disconnect a battery or alternator with the engine running. The resultant voltage spikes can fry electronics, the alternator diodes can be overloaded and fried...bad things can happen. The don't ALWAYS happen, but why risk $1,000's of dollars in damage when there are correct ways to test your alternator.
One simple way is at night star your car, turn off all electrical accessories, turn on your high beam head lights and point your car at a wall where you can see the reflected light well. Notice how bright they are. Turn off the car. If the lights get brighter, odds are very good your alternator is bad/weak.
Charge it, replace it,test the alternator,Charge it, replace it,test the alternator,
Most alternator or battery shops will test it for free.
Car would either have to be running or alternator removed for bench test
run it and then disconnect the negative wire from the battery if alternator dies its bad.
I pulled the negative cable from the battery with the truck running and the engine quit. Is this a test to see if the alternator needs to be replaced?
with a voltmeter
Either drive to your local auto parts store and have them test it in the vehicle or you can remove the alternator and take it to your local auto parts store and they can bench test it for you.
Shops like Advance will test it for free.
Battery light usually means alternator not charging. Most common solutions would be be a bad alternator, bad connection, or loose alternator belt. If the battery and alt test ok than check the connections to the alternator and battery.
Full fielding is a diagnostic test of the alternator You make the alternator work full out and measure the voltage and amperage output to test it against a published specification.
The alternator must be running to test without disassembly. If you remove it, many auto part stores will test at no charge. One test is a voltage test. Start the engine and use a multimeter to check the voltage at the battery. It should read between 13.5 and 16 volts. Any less or more and the alternator is bad.
Take it out, and to the nearest Autozone and they will test it free of charge.
Ask your local auto parts store to do it.
it could be your crank posistion senson or alternator failing get a dia and a load test on alternator
If it is makeing a noise or is not putting out at least 13.5 volts it is bad. Take the car or the alternator to an Auto Parts store and have them load test the alternator to be sure.
Auto parts shops like AutoZone will test the alternator for free.
take it to autozone and they will check it for free.
Have a shop load test the battery.
The best way is to drive it to your nearest auto parts store and have it tested. You can test it somewhat yourself. Start the engine and use a volt meter to test the voltage that is being supplied by the alternator for the battery. If it is less than 13.5 volts the alternator is bad.
If you question the condition of your alternator, drive to your local auto parts store and they will test the charging system for you at no cost.
It checks many things, connections, belt, and voltage regulator. I have never checked one with a load test. On a modern car or truck, never ever disconnect the battery from the alternator with the motor running to check the alternator. It can burnup a lot of electronics instantly.
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.
My lights were coming on when my alternator was going out. Test your alternator and charging system and replace accordingly.
If alternator and battery test fine- then you may have a bad fusable link not allowing the alternator to charge the battery
Most likely your alternator is failing or has failed. Try to get tbe vehicle to an auto parts retailer and see if they'll test the alternator for you. The test is usually free.