How Much Voltage Is Too Much From An Alternator?

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An alternator is one of the extensively important components in a truck. Plus, it plays a vital function in the truck or engine. This alternator is comprehended as an autogenic energy plant that generates electricity.

It also converts AC (alternating current) to DC (direct current). The alternator must also recharge sufficient electrical power to recharge the battery. It must also conserve an adequate voltage to operate a car’s appliances and components. Talking about the voltage for a car, “How much voltage is too much from an alternator?”

A voltage of about 15-16 volts is simply too much. An alternator is expected to generate not more than 13 volts, anything more than that would have a damaging effect. 

However, a high voltage from an alternator can be induced by a malfunctioning voltage regulator. The regulator is the tiny electronic or mechanical module built in the alternator.

This regulator has to yield a steady direct current (DC) voltage of about 12-14 volts from the alternator. Plus, the steady voltage is irrespective of the engine’s acceleration. 

It could also be induced by a poor battery. If a battery is rusty and worn down, the alternator would be triggered to operate extra tough to boost the battery’s charge. Subsequently, the alternator would regulate very hard and overcharge the battery.

Have in mind that, if an alternator should overcharge, it would naturally generate an additional voltage to the battery. This would make the battery receptacle swell up, become too heated, and miss its electrolyte through heating. 

Table Of Contents

What alternator voltage is too high?

Technically, 16 volts is detected to be too high for an alternator voltage. Nonetheless, there are different models of cars with different engines or batteries, and alternators.

For most alternators, a voltage of about 13 volts is normal, while for some, a voltage of a steady 13.5 volts is evidence of an issue. Yet, the 16 volts detected to be high might be normal for some alternators. Plus, it could be normal for an alternator not to charge sporadically for others. 

The vast disparity in voltages is as of validity that some alternators are regulated by Electronic content management(ECM) or Pulse code modulation(PCM). Electronic content management and pulse code modulation are built in the alternator to enhance fuel frugality.

However, this implies that the weight on the engine is operated to decrease harmful failure at the crankshaft. The alternator output is requested when there are inspected weights or the car battery must be charged. (Read Also:Can A Bad Ground Cause An Alternator To Overcharge?)

However, relying on room conditions, the charging of voltage differs. The substantial charge of voltage formulated to a voltage regulator is quite a pendant upon components.

The factors like, how distant the alternator is discovered from the battery, and the room air temperature which encloses the battery as computed by the pulse code modulation. This is why the room and under-the-weather temperatures are crucial statistics for the charging network.

Furthermore, additional components that determine the battery voltages are mechanical communications, with about 4 or 5 speeds which can significantly lessen the engine momentum when driving. A lot of contemporary engines run adequately below 2,500 rpm till they attain a road speed of 50 to 70 mph.

Thus, if the alternator does not retain the estimated charge voltage at a shorter engine momentum, the battery would forfeit its charge under huge accessory weights. In some problems of undercharging, the alternator might retain a false diameter pulley introduced, the road belt might be sliding, or the alternator may be below the ability for the car’s requisition. 

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How do I test my alternator for a high voltage?

Having a damaged alternator can make you stuck on the road. Although it is crucial to understand all the factors of the alternator which include- the means the alternator regulates, understanding a few simple tests, and understanding a few preliminary clues of faults could save from having an expensive breakdown. 

However, I would be your guide, by telling you the ways by which you can test your alternator. Before we proceed, you have to get some equipment.

After getting all the equipment, Below are the steps to test your alternator:

Step 1

Pull up the car on a flat road

Ensure you pull up your car on a flat floor, to make it susceptible to work on it, and after parking the car, put off the engine. 

Step 2

Put the wheel chunks of metal chunks

Put the metal chunks at the driver’s area back tire, to stop the tire from moving.

Step 3

Lift the car hood and find the alternator

After stopping your tire, proceed by opening the car hood. Then, find the alternator. In some cars, the alternator is usually found closer to the front top of the engine. While in some other cars, it might be placed below, which would make it hard to find. 

Step 4

Examine the engine drive sash

Check the engine’s drive sash for tension. You can do that by pressing down the middle of the belt, and ensuring there is not much motion.(Read Also:Will An Alternator Work Spinning Backward?)

Step 5

Pay attention to any sound

Turn on your car’s engine and pay attention to any sound like yelping or grinding. 

Step 6

Examine the alternators comportments

Put one tip of the rubber hosiery in the alternator’s receptacle, and put the other tip closer to your ear. This rubber hosiery operates like a doctor’s sphygmomanometer.

If the yelping or grinding is too loud when you hear through the hosiery, then you might have a comportment letdown starting in the alternator. So, it is better if you replace it.(Read Also:Should Alternator Pulley Spin Freely?)

Step 7

Start testing your car’s alternator

For you to begin assessing the alternator, you would have to switch off the car’s engine.

Step 8

Attach the voltmeter or multimeter

Turn on your voltmeter and adjust the settings to Direct current volts. Then, put the positive key to the positive end(+) of the battery, and the negative key to the negative end(-) of the battery. However, if the battery ends are loose-fitting, then, you would have to deal with that first.

Step 9

Examine the battery voltage

Your battery voltage should be about 12.6-12.78 volts. If your battery volts are bad, you would have to weigh and examine them. 

Step 10

Read the battery’s volts on the voltmeter

Turn on the car engine and read the volts on the voltmeter. The voltage should read about 14 volts. Nb- a stable alternator should read at lead 14.0- 14.5 volts. 

Step 11

Weight test the alternator

Put a weight on the alternator by switching on the dashboard lights, and other accessories like radio, and the Air conditioner. However, the volts are expected to stay increased with the circuits on. Moreover, if the volt does not alter when you start the engine – if it is not above 12 volts or if it is above 14 volts, then the alternator is bad.

 Nb- if the volts are quite low, you can carefully shake the electric attachments on the rear of the alternator to check if the volts would change. If the volt changes, the alternator might just be acting up due to a bad attachment. A loose-fitting or burnt connection on the alternator or the battery could result in false alternator readings.

How long will a car battery last with a faulty alternator?

A good car battery could last up to 40 minutes with a bad alternator. Fortunately, the battery can sustain you for an hour and a half. However, factors are influencing the duration of your car battery if the alternator is bad. These factors are how up-to-date the car is, the number of electrical components in the car, the battery’s ailment, and the car’s engine.

If you utilize the car dashboard light when the alternator is bad, the battery would run down fast. Plus, if the battery is old, it would not last long like a new battery.

For you to evaluate how long a battery would last can be quite hard. If you are using a typical diesel automobile, it has easy mechanical components. It could operate till the fuel tank is empty, and the battery would last for numerous hours without problems.

 While if you are using a fueled-powered automobile, the engine is regulated by Electronic components. This automobile has spark spikes and it would be a big trench on the car battery. The engine management components would have a huge pull on the power. There are anti-lock brake elements, airbags elements, etc. So, in this case, the battery would last for 40 minutes or 1½ hours.

How Much Voltage Is Too Much From An Alternator – Conclusion

How much voltage is too much from an alternator? Your car alternator is expected to read a voltage of about 12-14 volts. If it is more than that, you would have to replace it. You should also try to test your alternator during every car service. Kindly drop your comments and observation in the comments section. Cheers!!!

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