Alternating Issues

Alan Povey, Technical Manager at Denso, explains the role of alternators within advanced systems and talks us through some common issues.

There are three main types of alternator fitted to modern cars, and understanding the different roles they each have to play in the whole electrical system of the machine will make it easier to spot potential problems early on.

The three main types of alternator are: standard (also known as conventional) ‘Type III’ and the ‘super charger’. The Type III and super charger offer improved performance compared to standard alternators as they feature a ‘smart charge’ system.
The smart charger system works alongside the ECU to continually measure the system for optimum performance.

The battery in particular is continually monitored by the battery current sensor to identify the input and output of the battery current, battery voltage and battery temperature. This information helps the system to decide on the necessary charge required by the alternator for best results.

Misalignment and over-tightening of the belt are two of the most common issues related to failure of the alternator. Misalignment of the belt can result in rubber being shaved off it, which in turn can be sucked into the alternator itself causing it to overheat and in some cases, cause fires. Over tension of the belt can also cause structural failure within the alternator by pulling the bearings across, causing them to wear away quickly and resulting in excessive noise and possible damage to the vehicle.

2011 will see the introduction of more than 100 new Denso alternator applications and around 80 new starter applications, across leading marques such as Fiat, Alfa Romeo, Suzuki, Honda, Toyota, Jaguar, Land Rover and BMW. Denso’s  aftermarket starter and alternators are completely new-in-box, not remanufactured. This approach offers peace of mind in terms of quality, reliability and cost compared to remanufactured products.