how do you know if your alternator is good and how do you check to see if its good or not?

Question

without taking it off

Answer 1

You can use a voltmeter to get an idea . Hook it to the positive and negitive terminals of the battery it should read between 13.5 to 14.5 if it charging if the reading is lower check for broken wires to the alt . and if none are found remove the alt . take it to the parts store to have them test it .DO NOT DICNECT THE BATTERY CABLE THE ALT IS NOT MADE TO WORK BY ITSELF IF ITS NOT BAD IT COULD BE IF YOU TAKE ADVICE LIKE THAT .

Answer 2

depends on the age of the vehicle but the safest way to check voltage is at the battery when the vehicle is running, should be over 14 volts running. the older vehicles you could disconnect the positive battery cable with the vehicle running and see if the vehicle runs with the lights on. but please DO NOT do this with a computor controlled vehicle or you could fry the computor and the alternator and probably cause some global warming

Answer 3

when u press on the accelerator with the headlights on.. the head light's light beam shoud be consistant and not fluctuating. if the headlight power fluctuates, then the alternator is faulty & the battery is not being charged.
or.. just check the warning light on the dashboard..

dr. stan

Answer 4

IF ALTERNATOR IS STILL ON CAR START ENGINE USE A LONG SCREWDRIVER BE CAREFUL AND TOUCH THE LARGE NUT IN THE CENTER OF ALTERNATOR IF WORKING IT WILL ACT LIKE A MAGNET AND DRAW SCREWDRIVER INTO NUT.

Answer 5

Just yank it off and take it to Napa or any parts chain store. They all have testers for them.

Answer 6

just drive to auto-zone and they will come out and check it for free