One problem related to alternator/generator/regulator has been reported for the 2006 Dodge Ram 2500. The most recently reported issues are listed below.
Computer controled vehicle charging system caused the passenger side battery to over charge (dash gauge indicating overcharging) and swell causing irreparable damage and explosion of the battery. This could have started an engine fire under the hood. Fortunately it didn't. Vehicle was on main interstate highway when this occurred. I contacted the battery manufacturer thinking it was a bad battery, but the technician stated Dodge charging systems of this period wired the batteries in parallel incorrectly causing the aux battery to overcharge while the main battery was reading undercharged. "batteries in true parallel should be connected negative terminal to negative terminal and positive terminal to positive terminal. " the Dodge Ram 2500 24v cummins I own (completely stock) has the negative terminal cable from each battery connected directly to the engine block for ground. And not connected to each other at all. Again, a properly wired parallel battery system should have the negative terminal connected to each other. According to the battery manufacturer technician, this would become a problem with current flow between the two batteries and cause unbalanced charging due to the vehicle computer reading the main battery voltage only and signaling the alternator to charge at higher volts if the main is reading low. (which happens when the engine is started. . . Especially in cold weather). And once the main battery sensor signals the computer and the computer signals the alternator, the aux battery is charged even when it doesn't need it. And because the charge flow is restricted due to the negative cables incorrect wiring on the Dodge, the main battery only receives a small percentage of the charge. Thereby creating an continual overcharge to the aux battery until the main is slowly brought back up to full charge. Google: Dodge ram passenger battery boiled.