HOW DO I KNOW WHEN MY ALTERNATOR OR BATTERY GOES BAD?

The Alternator

Here are some symptoms to look for that are grouped together. Of course there is a warning light that will be displayed once an alternator goes out; however, be in touch with your senses to find the problem before they get worse:

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• Use Your Eyes: Usually when our customers complain of an alternator issue it just takes a quick look to find a belt missing, hanging off the engine block or so loose it's flapping around the engine compartment. A quick visual check of the belt for cracking, excessive wear marks and other visual related problems can give you some idea of what may be the problem. Also, the drive belt must have the proper tension to run the alternator correctly; too much tension is just as bad as not enough. A quick check of the belt tension is usually enough to determine if a problem exists.

• Use Your Ears: We also see our customers complain about hearing a "growling" or "whining" noise before an alternator gives out. The alternator is driven by either an accessory belt or a serpentine belt in conjunction with the crankshaft pulley. The alternator pulley typically spins about two or three times faster than the crankshaft pulley to produce the power necessary at lower engine speeds, such as at idle. If the pulley is not in correct alignment with the belt, if it's canted on the shaft or if the bearings and bushing are worn out, the growling or whining noise will let you know there's a problem.

• Use Your Nose: The smell of burning rubber or hot alternator wires will often accompany alternator failure. A pulley that isn't in alignment or not turning freely will cause more friction on the belt, which creates heat and then the smell of burning rubber. The hot alternator wire scent can be caused by an overheated alternator, so keep your nose in tune with your vehicle.

The Battery 

While not technically an alternator problem, a car that won't start is a definitive notice from your car that there's a problem in the starting system. When the key is turned, you'll hear a tell-tale clicking of relays ticking over but nothing else happens. After a time, even that noise stops. The immediate problem is usually a dead battery; but the question a driver should ask is, "Why is it dead?"

 

When an alternator begins to fail, or fails outright, the car's battery begins to take up the slack rather than acting as a capacitor for the system by receiving a constant infusion of electrical power from the alternator. However, even the best car battery will run down eventually leaving a driver stranded in the driveway or worse, on the side of the road. Car batteries are not designed for long-term power use. They're average life is between 5-7 years and they are designed to provide the vehicle with enough electrical oomph to start by juicing the starter motor with a surge of power and getting the whole works spinning.

Diagnosing a dead battery versus a dead alternator is relatively easy. Simply jump-start the car and then remove the cables as quickly as possible. Then wait. If the alternator is failing to charge the system, the car will soon die again and the problem has been pinpointed. If the car runs and continues to run, then it's likely the problem is with the battery. Caution should be used, however, as a dying battery can only receive a charge for so long and may go completely dead at a later point despite the best efforts of the alternator. 

We can test your battery at Rick's Complete Automotive (707)887-2281 and see if your charging system is up to par.