+DO NOT TEST AN ALTERNATOR BY DISCONNECTING THE BATTERY WHILE THE ENGINE IS RUNNING!

On older vehicles with mechanical voltage regulators, it was a common practice to disconnect a battery cable while the engine was running. If the alternator was charging, the engine would stay on. However if the alternator was not charging, the engine would stall. Although this practice was not recommended, it didn’t seem to do too much damage (at the time).

Such is not the case with electronic voltage regulators. These are fragile components susceptible to damage when a voltage surge/spike occurs. Pulling a battery cable while the engine is running will send a voltage-spike throughout the electrical system of the automobile. This can, and usually does, damage the voltage regulator as well as other items that may include the electronic dashboard display, ABS control unit, and engine management electronics. In fact, many new automobiles have specific instructions regarding the grounding of your body to the chassis of the car to prevent static electricity when working on delicate electronics. If they are this sensitive to static electricity, just think what could happen if a battery cable was disconnected!

To sum it up, don’t test your alternator by removing a battery cable. Come on down and let us determine if your alternator is defective or not.

+NEED MORE POWER AT IDLE

There are several ways to get more power at lower engine speeds. If you only require a little more power at lower engine speeds you may be able to use a smaller pulley. The smaller pulley turns the alternator faster at lower speeds thus providing more power. When using a smaller pulley you should take care not to over rev the motor. If you over rev the alternator with a smaller pulley the alternator can fail.

The best way by far to obtain more power at lower engine speeds is to install an oversize alternator. The physically larger alternator produces more power at lower engine speeds and are much more reliable at higher outputs. Installing a higher output alternator that is the same size as your original alternator will not give you more power at idle.