The voltage regulator is defective. It may be internal or external to the alternator. Any auto parts store can provide this information. Have them check the alternator for output.
May be the voltage regulator is defective, bad connection somewhere, alternator with a defective part which impair to fully charge the battery. decrease of the battery solution, short-circuit somewhere.
Im not sure if your talking Alternator output wire fuseable link or regulator exciter wire, i would assume your talking the exciter wire, it may have a short and is grounding out on the engine or frame somewhere
have the battery tested, average life of a battery is 2 to 3 years. if battery is good check voltage regulator and starter motor. there is a short somewhere if the battery is good
The headlight switch has a built in circuit breaker. It is to protect the system in case of a short. Also the voltage regulator is built into the alternator. Or, you could just have a bad ground somewhere.
Okay the first thing I want you to do is turn the key on and observe the warning lights. Does the battery light come on? If not the voltage regulator in that alternator is bad. Assuming you have a good alternator and a good battery You may have a voltage drop somewhere. The most common is an underhood light or trunk light that doesn't go out when you drop the hood or close the trunk. Others may include a door switch or possibly a short somewhere. Good luck.
Electrical one way valves called diodes often go bad in alternators (part of the regulating system). Other causes would be bad field or stator windings...basically a broken wire somewhere in the alternator. Bad bearings...since the thing spins very fast.
You just need an accurate voltage meter. Connect the meter to the poles of the battery. Start the engine and avoid spinning her up, even not for a short moment. The reading of the meter now can be anything; a reading lower than 12.6 volt indicates a weak battery. Slowly increase the engine speed. The meter reading should increase too, but will get "catched" at an engine speed somewhere at 1000 rpm. (8001200) From then on the reading will stay "locked". It should be 13.8V; 0.5V higher or lower is the limit of what is acceptable. A voltage too high is NOT good: it will ruin your battery and wear out bulbs and other equipment! A voltage regulator is good when the reading hardly reacts to change of engine speed or to adding power consumers like electric window heaters or main headlights. Ans 2: sometims the voltage regulator is faulty when the remainder of the alternator is OK so it's worth considering replacing the regulator first because it is less expensive and sometimes it can be removed and replaced without taking the alternator off the car.
normally a alternator that is from the factory will have motorcraft somewhere on it, if it has been rebuilt it should have a sticker somewhere on it from the shop that rebuilt it
Ah, you have made one of the most common and easiest mistakes to make in automotive maintenance. Because the 'battery voltage' idiot light came on, you assumed that the battery was bad. Did you have an automotive electrical specialist test the electrical system on your car? Did you have the battery tested at a battery shop? Did you know that there are 3 primary parts to an automotive electrical system, and anyone of them can be responsible for the system operating below required voltage levels? Most modern automobiles generate electricity with a device called an alternator, which is driven by a belt from the crankshaft. The alternator generates Direct Current, at voltages up to 20 volts, in some cases. To keep the alternator from frying the battery, a Voltage Regulator is used to control the output of the alternator. This insures that the battery is only charged with a current of 18 volts, or less. Most modern alterators have the voltage regulator inside, but on older cars, the voltage regulator is mounted on the fender or the firewall, somewhere in the engine compartment. So, the alternator generates the electricity used to charge the battery, but the voltage regulator controls the output of the alternator. If the alternator is going bad, it may not be generating enough voltage to charge the battery. The battery is usually a 12 volt battery, and must see more than 12 volts to charge. Or, the alternator output might be reduced to an unusable level by the voltage regulator. Before you replace the entire electrical system, take the car to an automotive electrical specialist for testing. They can determine exactly which component is not working, and repair it. (Note: If the voltage regulator is bad, this DOES NOT mean that the entire alternator must be replaced! In almost all cases, the voltage regulator can be replaced by disassembling the alternator. If the specialist insists that the alternator must be replaced, I would recommend getting a second opinion, even though testing is often not free. Voltage regulators are fairly cheap, and can be replaced by a competent technician without too much difficulty. Alternators are expensive.)
Sounds to be alternator. Take somewhere to have the charging system tested.
because you have an open electrical line somewhere behind your radio.
Alternators are not in a fused circuit. If your alternator isn't working, it's because either the belt is broken, there is a shorted circuit somewhere, or the alternator is faulty.