What causes an alternator to undercharge?
In most cases of undercharging, the alternator may have an incorrect diameter pulley installed, the drive belt may be slipping or the alternator itself might be undercapacity for the vehicle application.
How much voltage is too much from an alternator?
For some alternators, it’s normal to see as low as 13 volts. For some, a constant 13.6 volts is an indication of a problem. For others, it’s normal to see as high as 16 volts for long stretches. Still, it’s perfectly normal for others to see the alternator not charge at all intermittently.
What can mess up an alternator?
Alternators have moving parts, get dirty and are subject to stress from heat and cold. As a result, the internal parts gradually wear out. One of the most common failures is bearing failure. The needle bearings that allow the rotor to spin freely inside the stator can break down from dirt and heat.
Is 14.7 volts too high for alternator?
Charging voltages over 14.7 volts can prematurely dry the battery by boiling out electrolyte, and increase risk of a battery hydrogen gas explosion. Less than 14.3 would be a “weak” alternator or regulator. Much less than 14.2 at a fast idle is bad wiring, bad alternator or regulator, or a bad connection or fuse link.
Is my alternator overcharging?
An overcharging alternator can lead to headlights and tail lights prematurely blowing out alone or in tandem. Other burnout symptoms of an overcharging alternator are repeated blown fuses, dash and interior lights blowing out and lights becoming extremely bright when engine speed increases.
Is the alternator voltage too high or too low?
Car Alternator voltage is too high (16V+) Can it be reduced? My car alternator runs at 16 to 16.5 volts when I hit the gas, and 15v idling. This is scaring me and a new one is too expensive.
What should the voltage be on a bat alternator?
Measure the voltage across the battery and the big bat alternator terminal to alternator case. There are two things that you are looking for. The charging voltage should be between 13.9v to 14.4v. Also the voltage at the battery and the voltage at the alternator should be within 0.5v of each other.
Can a remote sense alternator be too high?
assuming there’s not much voltage drop between there and the battery. Other alternators are “Remote Sense” and use a third wire to measure voltage over closer to battery. the alternator thinks the battery is low so obediently goes to full output trying to charge it back up. Here’s some Delco-Remy info on remote sense alternators.
Why does an alternator use ohmic voltage loss?
The reason is Ohmic voltage loss. To save costs, wires in cars are typically thin and the voltage loss can be great if there’s a lot of electrical load. Good alternators measure the voltage at the battery terminals and use whatever voltage at the alternator that is required to obtain good voltage at the battery terminals.