HAVE you experienced a glitch in your car? Does your radio reset your preset stations or maybe your tachometer stops working suddenly then miraculously come to life again? Demons in your car or just some stray electrons running around?

Most likely, you are experiencing telltale signs that your alternator or related components are on the way out. Without immediate attention, this can cause car trouble ranging from slow starts all the way up to a dead car.

An alternator is a relatively simple component containing only a few parts but it plays a critical role. It produces current that is used to power your car’s accessories and also keeps the battery fully charged, providing the power it needs to start the car.

When the alternator begins to lose its potency, so do the accessories that draw on that electricity. Symptoms range from alternately dimming or bright headlights and dash lights, to speedometers and tachometers that simply stop working.

Some newer cars have a pre-programmed priority list just in case an alternator problem arises. This is usually based on safety considerations. For example, the radio will shut down before the headlights dim because the headlights are more important than music.

Sometimes it may just be a simple matter such as a loose alternator belt. This would almost always announce itself quite loudly as a screeching noise. Having the belt tightened or replaced would restore power immediately. A tight belt is just as bad as a loose one so make sure the belt is tightened correctly.

Another telltale noise is a rumbling or growling sound from the engine compartment. This is usually related to the alternator bearings failing. Bearing failure can be attributed to an incorrectly aligned alternator or incorrectly tightened belt. Since the alternator spins faster than the engine and is not lubricated by engine oil (being a sealed-type bearing) incorrect tightening or alignment will speed up the failure. A faint burning smell is usually indicative of incorrect alignment.

While your car may have an indicator light that shows that the alternator has failed, sometimes the warning comes too late (or the indicator bulb has burned out). When the alternator has stopped functioning, your car battery is the only supplier of energy. However, since it is not receiving any charge, the battery may only last a few more kilometres before the car stops entirely.

To diagnose whether it is the battery or alternator that is failing is fairly easy. Simply start the car (either by jumpstarting it or with a fresh battery) then remove the cables quickly. If the alternator is the problem, the car’s engine will quit immediately.

If the alternator checks out okay and you are still having gremlins such as the flickering lights and radio problems, it is worth checking out the wiring in your car. More than likely, you might have an earthing problem, where the ground wires connected to the body are frayed or connected to rusting bolts/rusted body points.

This will cause the current to make intermittent contact (and not complete the circuit properly) and even cause wires to heat up unnecessarily, maybe even causing a fire.

Alternatively, you may have added one too many accessories to the car, thereby exceeding the alternators ability to recharge the battery. If you wish to retain these accessories (usually it’s ICE), you may need to install a larger alternator and a larger battery to keep up with the additional accessories’ demands.

The final thing to check with an alternator is the diode rectifier. Since your alternator produces alternating current and the car needs direct current, it is “rectified” by a diode rectifier. Needless to say, if you diode rectifier is burnt out, the current produced by the rectifier is not going anywhere.

A get-you-home tip if you are stranded somewhere with a non-functioning alternator; get a friend with a similar car to escort you home. Switch your car’s battery with his and jumpstart the car (if automatic) or push start (if manual). This will get you a possible 30km or so before his battery dies, too. But then your car’s battery (in your friend’s car) will have had a full charge from his car. Switch batteries again and repeat till you get to a mechanic’s shop or home as the case may be.

So if you are experiencing demonic possession of your car, it is more than likely an electrical problem emanating from your alternator. Don’t see the bomoh but instead find me at the shop soon.

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