What should the charge voltage be on an alternator?
Turn on the high beams for 10 seconds and then turn them off. Measure battery voltage across the battery posts with your DMM. You should get between 12.4 and 12.6V. This means your battery is fully charged. If you get a reading below 12.4V, charge the battery before continuing. 5b. Measure the Charging System’s No-Load Voltage
Why does the battery light stay on when the alternator is charging?
If your vehicle’s battery light stays on, even when the alternator is charging, it could indicate that the battery circuits or the alternator system are malfunctioning. This will lead to improper charging. Having the battery light turn on when you’re charging can sometimes happen. But the light should go off after some time.
What causes an alternator to output low volts?
If the voltage at the battery and alternator don’t match. For example the battery reads 12v and alternator reads 14v. This means that there is an issue with wiring. While applying the same conditions as above.
When does the alternator turn on the idiot light?
When the engine starts and gets up to a high enough rpm for the alternator to start putting out voltage, there is a diode inside that takes some of the output voltage and featured back to the terminal that goes to the idiot light.
Turn on the high beams for 10 seconds and then turn them off. Measure battery voltage across the battery posts with your DMM. You should get between 12.4 and 12.6V. This means your battery is fully charged. If you get a reading below 12.4V, charge the battery before continuing. 5b. Measure the Charging System’s No-Load Voltage
Why does my alternator not turn on the battery light?
That battery is likely at or near the end of it’s useful life. A weak battery or working charging circuit won’t turn on the battery light. Since you pretty much ruled out the alternator I would make sure to check your fuses. IIRC there are 2 fuses for the alternator (will check my diagram later).
When the engine starts and gets up to a high enough rpm for the alternator to start putting out voltage, there is a diode inside that takes some of the output voltage and featured back to the terminal that goes to the idiot light.
How does an alternator work on a lightbulb?
What is happening is that the alternator is full output voltage is getting sent to one terminal of a lightbulb, and the other end of the bulb is connected up to the battery positive terminal through the ignition switch, which is now at a lower voltage because of the voltage drop in the positive wire.
Why is the battery light still on after a new alternator?
So, now truck has new alternator and battery BUT battery light is still staying on. I had them check both and they said, new battery and alt showing good. I know all of the connections are tight and I checked the fuses inside the truck and all are good.
How to know if your alternator is working properly?
1 Check the drive belt or serpentine belt. Look for signs of wear or damage like cuts, shiny spots or missing chunks under the belt. 2 Also, check the belt tensioner for proper operation and damage. It should rotate freely. 3 Make sure the alternator is properly mounted. 4 Check the alternator for noises. …
What happens when the diodes in an alternator go bad?
Alternators use diodes to rectify alternating current produced by the alternator into direct current. When one or more diodes go bad, the alternator can cause all kinds of problems. AC voltage leak can cause your lights to dim and drain power from your battery, for example.
So, now truck has new alternator and battery BUT battery light is still staying on. I had them check both and they said, new battery and alt showing good. I know all of the connections are tight and I checked the fuses inside the truck and all are good.
How does an IDJIT light work with an alternator?
The idjit light essentially goes from the alternator output to the battery positive. If all goes well, both terminals are at the same voltage potential and no current flows. If either the battery or alternator are not at the same level, there will be current flow through the light and it will illuminate.
Can a car battery be drained by an alternator?
While you might initially think that any problems with electrical things like lights or radio not working are directly related to the battery, the alternator is actually where most of the power in your vehicle comes from. Consider that if you were to leave the lights of your car on overnight by the next day your battery might be drained completely.
What should I do if my alternator keeps dying?
The alternator is essentially a generator and it keeps your battery charged while supplying additional electrical power for the other systems in the vehicle. If you have a new alternator and your battery keeps dying on you, then there’s definitely a problem that you’re going to need to look into.
What causes an alternator to stop working on a car?
Once the alternator stops working, so do all of the electrical systems required to keep a car going. Other problems can also cause a car to not start. It could be a bad starter, corroded cables, or a broken connection somewhere between the battery and starter.
While you might initially think that any problems with electrical things like lights or radio not working are directly related to the battery, the alternator is actually where most of the power in your vehicle comes from. Consider that if you were to leave the lights of your car on overnight by the next day your battery might be drained completely.
Once the alternator stops working, so do all of the electrical systems required to keep a car going. Other problems can also cause a car to not start. It could be a bad starter, corroded cables, or a broken connection somewhere between the battery and starter.
The alternator is essentially a generator and it keeps your battery charged while supplying additional electrical power for the other systems in the vehicle. If you have a new alternator and your battery keeps dying on you, then there’s definitely a problem that you’re going to need to look into.
Is it safe to turn on heated windshield alternator?
But don’t turn on the heated windshield if your vehicle has one; alternator voltage may increase to over 100V and this can be unsafe. Take a voltage reading across the battery posts. Your reading should be at least 0.5 volts above base voltage for your system to keep up with electrical system demands.
Can a manual tensioner be used to replace an alternator?
The belt tensioner will only travel (swing) so far which can make installing the belt difficult. Never pry or force the belt onto the pulley. Vehicles with a manual tensioner or the belt tightens with the alternator, there should about ½ inch of deflection in the belt between the pulleys with the greatest distance between them. 7
How does an alternator tester work on a car?
First, a battery tester will be used to confirm if the battery is still capable of holding a charge, or if it has dead cells and must be replaced. Once the battery has been either recharged or replaced, the output of the alternator is checked with a multimeter.
What’s the best way to replace an alternator?
Ensure all the bolt and/or nut threads are started and tighten them evenly. On some vehicles, the electrical connections will need to be installed first before permanently tightening the alternator for access reasons. Place the drive belt in position and ‘rotate’ the belt tensioner so the belt can be installed.
What causes an alternator to go over base voltage?
If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.
Is the alternator still running off the battery?
Now i hooked up the voltage tester to the battery with the new alternator and the car still seems to be running off just the battery (at about 12 volts).
How can I tell if I have an alternator problem?
To differentiate an alternator problem from the battery, you will need to use a voltmeter to check for voltage. First, turn off the engine and check the battery voltage. A fully charged battery should have a reading of 12.65 volts. Next, turn on the engine and recheck the voltage. You should have a reading of 13.5 to 14.5 volts.
Why is my car battery still not charging?
If you are sure that your alternator is working properly and yet your battery is still not charging, then it’s possible that you have a bad voltage regulator in your vehicle. The voltage regulator keeps the right amount of electrical power flowing through the various electrical systems in your vehicle.
What does it mean when your alternator is not charging?
If the alternator is not charging the battery, you will have a red “ALT” or “charge” sign on your dashboard. This means that your battery is no longer being supplemented for power by the alternator. You will need to recheck the wiring because the light could also be faulty.
Can a battery voltage test be done on an alternator?
One test is not enough if you are diagnosing a charging system problem. All too often, the alternator is condemned as the source of the problem if only battery voltage is present with the engine running. If this is the case, it only means that the alternator is not charging, but does not reveal why.
Why does my alternator get higher than base voltage?
You should get 0.5 to 2 volts higher than base voltage. If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.
To differentiate an alternator problem from the battery, you will need to use a voltmeter to check for voltage. First, turn off the engine and check the battery voltage. A fully charged battery should have a reading of 12.65 volts. Next, turn on the engine and recheck the voltage. You should have a reading of 13.5 to 14.5 volts.
Can you test the battery with an alternator?
Click to expand… That’s battery cable trick. When cars had generators you could test the generator by running the car with the battery disconnected. It’s different with an alternator and with todays cars. You can spike the electronics very easily.
Why does the battery light come on after the alternator is replaced?
This would make the Battery Light come on. It is also possible that there is a problem with the fusible link or the alternator fuse for the charging system.
This would make the Battery Light come on. It is also possible that there is a problem with the fusible link or the alternator fuse for the charging system.
Why does my alternator not put out electricity?
IIRC, the alternator won’t put out if voltage isn’t on one of the pins. Ah that one – called the generator relay in the Mitsu manual. From the Mitsu manual: “The generator relay functions as a backup for the flow of electricity to the rotor coil (field coil) if there is a disconnection or damaged wiring of the charging warning light.”
Where does the charging warning light go on an alternator?
Black and yellow goes from the alternator plug to that generator relay. Blue wire goes from generator relay to that interior harness (C25) which goes to the instrument panel wiring (My 3rd pic the plug on the left) which looks to be for the instrument cluster for the “charging warning light”. Click to expand… Gotcha.
What happens to power steering after an alternator is replaced?
Usually when brakes pads are replaced and the rotors surfaced, it may make the brakes feel stiff for a while until they wear in, but it shouldn’t impact the power steering at all. The only thing I could think of… Engine sludge?