Do I have to take my battery out to have it tested?
That’s because you should be testing a battery after it’s been sitting for at least an hour without it being used. If you test your battery immediately after you’ve been driving your car you might get a false reading because the battery could still be holding a charge from the alternator.
Do you need to check the battery first before checking the alternator?
Check the battery first. The battery is needed to start the vehicle, which, in turn spins the alternator at sufficient speed to keep the battery charged.
What should I do if my alternator is not charging?
The alternator normally lasts longer than the battery. There are some easy steps you can go through to check the function of your alternator. Tap the alternator carefully with a hammer while the engine is runnin; if the charging goes back to normal, the coals inside it are worn out.
Why does a battery need an alternator to work?
The battery cannot supply all this power on its own, hence the need for the alternator. The alternator converts mechanical energy into electricity. The alternator is connected to a set of belts which when loose can cause it not to function as required.
How do you check the resistance of an alternator?
Touch the big post on the alternator (the positive terminal post on the alternator) with the red lead of the multimeter, and touch the other lead on the alternator case. With the multimeter set to measure resistance, it should measure more than 550 ohms if the alternator diode is any good.
What should I do if my alternator battery is bad?
If the battery is defective in any way, your alternator will fail well before its time. If the battery is discharged, your alternator will only have a short life. Check the battery cables and the wires to and from the alternator for any wear or corrosion.
Do you need a multimeter to check your alternator?
A multimeter measures voltage as well as other electrical properties such as current and resistance. You want to measure voltage when you’re checking your alternator. Check the battery first. The battery is needed to start the vehicle, which, in turn spins the alternator at sufficient speed to keep the battery charged.
How can I tell if my alternator is charging?
The alternator is charging if the battery voltage stays above 13 volts with the engine at 2,000 rpm and all accessories on. Check the alternator gauge. If you have a volt/amp gauge, it will read the alternator output for you.
How long can a battery last without an alternator?
A good alternator and can last well over a decade, sometimes as long as 15 to 20 years. However, if an alternator does fail on you then you’ll know it fairly quickly as your electrical systems will fail soon afterwards. The charge in your battery does not last long without the alternator there to keep it running properly.