0
Most people would take the vehicle to a mechanic to have it checked. A cheap way to tell if it is charging is to remove the positive battery cable from the battery while the engine is idling. If the engine dies, the alternator is not charging and should be tested. Some will squeak or make scraping sounds at an idle.
This might have worked on a car thirty or more years ago but is actually potentially very harmful for a modern car. The cars now are designed to have a battery as an integral part of the charging system and if it is disconnected can send voltage spikes through the system and burn out your computer. Also the alternator is designed to put out a certain amount of current and this test would only tell if the alternator is putting out enough current to keep the engine running, not if it puts out enough to keep the battery charged, run the lights etc. The only real way to tell if the alternator works is to put a voltmeter on the battery and see if the voltage goes up after the car is started. Then to tell how well it works, put an amp meter in line with the alternator and see how much energy it puts out when the various circuits are turned on.
Wiki User
∙ 12y ago
Add your answer:
Earn +20 pts
Can anyone tell me how to tell if the alternator is bad or going out on my 1993 silverado?
Perhaps thids might help... http://wiki.answers.com/Q/How_do_you_tell_if_the_battery_or_the_alternator_is_bad
Plymouth Voyager alternator going bad How do you tell?
There are generally two signs that the alternator is going bad. First is the noise. A new noise will begin to be heard. Something like a whining when the car is accelerating. Second is the smell. You may smell burning from the engine department.
How do you know when the alternator is going bad?
When your battery does not get charge.
How can you tell when an alternator bearing goes bad on a Jeep Wrangler?
Take the belt off and spin the alternator by hand. If you hear a grinding noise, like sand rubbing on metal, its probably going bad. Also try to wiggle the pulley up/down/left/right. If it wiggles, the bearings are going bad. Of coarse you can always wait until they get so bad they shatter and the alternator wont spin at all, like i did. :(
Does an alternator make noises when it is going bad?
If bearings go bad they will "squeal"
Alternator keeps going bad?
There are a few reasons why your alternator might keep going bad such as rusty latches under the car. You may also have leaks, dents, or parts that need to be replaced on the vehicle that are effecting your alternator.
What causes the alternator to stop working?
How to Tell If Your Car Alternator Is Bad Check related link below…
Why is your alternator making a noise?
Normally this is the bearings going bad.
What are symptoms of bad alternator?
There are several signs that an alternator is going bad. A few signs are dim lights, smell, warning lights, and a dead battery.
What are the chances of an alternator fuse going bad before the actual alternator on a Ford E-250 van?
good
Why are your head lights dim on your 1999 Chevy Venture?
Alternator is going out? battery is going bad?
What noises does a bad alternator make?
A bad alternator will make whats called a whirring noise. It could also make a low growl. This is just the bearings going bad. If your alternator is not supplying any power, it has nothing to do with noise typically.
