I have a 1989 Ford tauris battery light is on changed Battery and Alternator is the regulator inside of the alternator? what would cause this light to continue? Thank you.

Check the voltage regulator.

The alternator (or battery) light, illuminates to indicate that the alternator is not providing enough charge to the battery. Thus, the battery is discharging as the vehicle is running. Eventually, the battery will drop below approximately 8 volts and then things will start malfunctioning fast, causing crazy indications and eventually vehicle shutdown. This problem is usually due to a bad alternator or voltage regulator (usually inside the alternator). It could also be serious short in the electrical system, but this is not as common.

with a charged battery remove the negative cable place a test light between the cable and the battery if the light is on there is a draw unplug one thing at a time a bad diode inside the alternator will also cause a draw then pull out the fuses one at a time

I recently had a similar issue, it turned-out to be the voltage regulator (inside the alternator) I purchased an alternator, problem solved.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/keith_f374b1cfd1696a17

you should have 12.5 volts with engine off at battery and 14.4v with engine running and charging system working. Is alternator light on? please rate, thx.

There are different versions and 1989 is too old to get on line. here is 1993, so take with caution. Also check the fusible link.

Battery Positive Voltage (B+) Output
The generator (alternator) output is supplied through the Battery Positive Voltage (B+) output connection to the battery and electrical system. I Circuit
The I circuit, or ignition circuit is used to turn on the voltage regulator. This circuit is powered up with the ignition key in the RUN position. This circuit is also used to turn the indicator on if there is a fault in the charging system operation or associated wiring circuits A Circuit
The A circuit, or battery sense circuit, is used to sense the battery voltage. This voltage is used by the regulator to determine the output. This circuit is also used to supply power to the generator (alternator) field coil. This circuit is connected back to the load distribution point and is a protected circuit. S Circuit
The S circuit, or stator circuit, is used to feedback a voltage signal from the generator (alternator) to the regulator. This voltage, typically 1/2 battery voltage, is used by the regulator to turn off the indicator.

first off a carburetor does not accelerate and the ground cable from the battery shoukd attach to both the frame and the motor (chassis ground). the extra load on your alternator may trip a sensor somewhere to speed up the engine rpm. your a/c button does the same thing. if the rpms exceed 1000 during idle you may have a bad regulator in your alternator.

VOLTAGE REGULATOR IS LOCATED BEHIND BATTERY.YOU PROBABLY MIGHT HAVE TO REMOVE BATTERY TO REMOVE THE VOLTAGE REGULATOR.

Thats a guessing game, but first, if the battery light was on, that means no alternator output. So recharge the batteries and be sure they are good, Then replace the alternator. If the batteries and the alt are good, and the battery light is off, then all should be OK.

THE BATTERY CAN CAUSE IT AS WELL... MAKE SURE YOUR ALTERNATOR CONNECTIONS ARE FIRM... THE SINGLE WHITE WIRE THAT PLUGS IN IS CRITICAL

Hi,I am Ron,Look at the alternator out put voltage,and have the battery load tested.Also check bad connection from battery to alternator(this is the large wire/cable).alternator turns the battery light on,why?You need to figure out witch one.A diode could be going out in the alternator,diodes change ac voltage to dc voltage ,that`s why the call it a alternator(alternating current)AC voltage means alternating current. If it goes unrepaired it can ruin battery,changing battery voltage from 12 volts dc to 12 volts ac.Also there is a built in voltage regulator that holds voltage down to about 14 volts charging while car is running.Voltage regulators can cut off charging completley or open wide allowing alternator to charge as much as 18 volts dc,ruining battery(boiling battery acid out of battery)and ruining alternator by burning fields and rectifiers out.So have it checked or do it your self.Auto parts stores can check alternator and battery.If I can be of more help,please [email protected]