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Did you install a new voltage regulator? Is the belt tight? Maybe the "computer brain" is weakening.


If you have installed a new alternator and new battery, check the harness/wiring that plugs into the alternator, it may be corroded/bad connection causing your battery to not be recharged at idle speed; voltage should stay between 12-14.5v range and steady (some momentary drop may occur after turning hi beam lights, etc but it should return to proper voltage after a few seconds), as for the regulator, on most cases it is inside the new alternator so no further adjusting may be required; also, make sure you get the right alternator for your focus-there's like 3 types, the wrong one will cause your dashboard alternator lamp to be lit at all times-replace with right one or higher output if got power windows,seats,etc.Good luck! Buena Suerte!

2007-09-18 22:34:25
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Related Questions

Will a voltage regulator kill a battery?

Two things can happen. 1. the voltage regulator fails so that the alternator doesn't know the battery charge is dropping therefore the battery doesn't get charged. 2. The voltage regulator fails in such a way as to allow the alternator to overcharge the battery which causes the battery to overheat and fail, Sometimes an overcharged battery can explode.

Can running a new alternator on a half charged battery cause damage to either the battery new alternator voltage regulator etc?

Not likely, but running the engine with a dead battery can damage some alternators. Always fully charge the battery when installing an alternator.

Why does your battery gauge keep dropping to zero on your 2003 Monte Carlo after you have just replaced the battery?

Bad alternator not charging battery? Bad voltage regulator? Blown fusable link?

Does alternator on weak battery affect the RPM?

If you have the wrong size battery in a Cadillac with the northstar will it effect the alternator voltage?

Why voltage regulation is required in alternator?

To regulate the voltage flow going to the battery.

Why does my Car stall when you unhook the battery?

It means that you have an alternator fitted. An alternator needs an amount of battery voltage to generate electricity. A generator/dynamo will make voltage without a battery being present.

Would an alternator burn a battery up?

If the voltage regulator (usually located inside the alternator) were to go bad and not limit voltage to the battery quite possilby _yes

How much voltage the alternator of Skoda octavia gives?

the alternator voltage at the battery should be between 12.4voltsv-13.6 volts

How do you know if the battery is no good on a 2000 ml320?

Should really charge it then test it with a proper battery load tester. All you can do on your own is get a multimeter and check the voltage. Without it running and having sat for a 1/2 hour or so the voltage should be approx 12-12.5 volts. Start the engine and if the alternator is good the voltage at the battery terminals should be 13-14 volts. If without the engine running the battery voltage is 12 or less this may indicate that the battery is not holding a charge. Even then the voltage should go to between 13-14 volts when engine is started showing that the alternator is working to charge the battery. If when started the battery voltage stays around 12-12.5 volts or less I would suspect the alternator. Just to double check there is the main power out terminal on the back of the alternator. With the engine running check the voltage. If 13-14 volts is present at the alternator but not the battery the circuit in between the alternator and battery is suspect. If the voltage at the alternator is the same as at the battery (12-12.5 or less) the alternator or voltage regulator may be defective.

How does an alternator keep a cars battery charged?

An alternator has diodes which transform ac voltage to dc voltage so that the battery gets negative and positive current on its poles thus making the battery to be charged.

What is alternator?

It is a device that converts mechanical energy to electrical energy on a car. It works by:the alternator creates an electric field by spinning a magnetic rotor with direct current inside stator windings. an ac voltage is developed and rectified dc. this voltage is compared to the battery voltage and determines the current through the rotor. if the battery voltage is lower than the alternator voltage, more current through the rotor increases the magnetic field and creates a larger alternator voltage. if the battery voltage is higher, less current through the rotor decreases the alternator voltage.

What does the Low Battery Voltage message indicate on Volvo S80 2001?

It means the battery voltage is low. Can be the battery is defective or the alternator is failing.

How do you measure the voltage on a car alternator?

get a multi meter that reads dc voltage & touch the black (negative -) wire to the negative battery post & the red (positive +) wire to the positive battery post with car running. car off is battery voltage, car on is alternator voltage.

How do you fix an alternator that overcharges your battery?

On most vehicles today the voltage regulator is built into the alternator. If that is the case then just replace the alternator. If the voltage regulator is external on your vehicle then replace the voltage regulator.

On a F-450 what causes the alternator to not recharge the battery?

either the alternator or the voltage regulator are no good.may also be a bad battery

Why isn't your Mazda truck alternator not charging your battery?

bad alternator, bad voltage regulator, bad battery, bad connections.

Is your battery weak if your voltage gauge moves down?

Weak battery, or weak alternator.

Why would your battery light stay on after you have put in a new battery and alternator?

The battery light comes on when the alternator output voltage is too low or too high. You have a wiring or regulator problem.The battery light comes on when the alternator output voltage is too low or too high. You have a wiring or regulator problem.

Why wont your brand new alternator recharge your battery?

Maybe the battery is defective. Check the voltage at the battery terminals with the engine running at idle. You should get 13.5 to 16 volts. If not the alternator is defective or the voltage regulator is bad. If you are getting the correct voltage, the battery is bad or the connections are corroded.

Battery light stays on in your Chevy silverado 2005?

test the voltage on the battery first, then on the alternator. If its good then it could just be the diode in the alternator. I would suggest you replace it becuase eventually your alternator will die and the battery will not get charged leaving you stranded somewhere. It is possible to just be a battery but you wont know unless you have the battery tested. check the voltage on the battery and the alternator before you do anything else.

Buick lesabre new alternator battery will not charge?

Have you checked the fuses?AnswerMay be a bad voltage regulator. alternator is no good without a voltage regulator. that's what "turns on" the alternator.

Please explain the charging circuit in automobile. 1. How does the charging light comes on when ignition switch is turned on 2. How charging light comes on when alternator is not or less charging?

When the ignition is turned on, battery voltage passes down the wire to the alternator to 'excite' the alternator when the engine starts. When the engine starts and the alternator generates a voltage, the light is extinguised by the charging voltage cancelling out the battery voltage coming down the wire. If and when the alternator completetly fails the the light will come back on as there is no sancelling voltage. if the alternator produces a voltage lower than the voltage from the ignition switch then the battery light will glow.

How car battery produces the power?

A battery does not produce power, it just stores power. The alternator produces the DC voltage the battery stores. As the power is taken from the battery it is replenished by the alternator.

What is the problem when your change the alternator and its still not charging the battery?

Obviously check the battery. Anyway, if the alternator, battery, and wires connecting them are good the voltage regulator is next on the list.

Why does your battery indicator show red?

Red means that the battery charge level is low or that the alternator is not charging battery properly. Check alternator, voltage regulator, connectors.