It varies charging voltage relative to ambient temperature and the system voltage requirements. A self-diagnostic program can detect charging system problems and record fault codes in system memory. Some codes will light the POWER LOSS, POWER LIMITED, or MALFUNCTION INDICATOR lamp on the instrument panel; others will not. Turning the ignition on causes the logic circuit to check battery temperature to determine the control voltage.
A transistor in the logic module or logic circuit signals a driver translator in the power module or power circuit to turn on the AC generator field current (Figure 8-68). The logic module or logic circuit constantly monitors system voltage and battery temperature and signals the driver in the power module or power circuit when field current adjustment is necessary to keep output voltage within the specified 13.6-to14.8-volt range
Modified Bosch 40/90-ampere and 40/l00-ampere AC generators (alternators) were introduced in 1985 for use with the DaimlerChrysler computer controlled charging system. These Bosch dual output AC generators have a Y-type stator and were modified by removing their internal voltage regulators and changing the external leads. They are fully interchangeable with DaimlerChrysler dual-output AC generators of the same rating.
Use of dual-output AC generators was phased out in favor of a single-output Bosch alternator when DaimlerChrysler ceased manufacture of its own alternators in 1989. Current DaimlerChrysler charging systems with a Bosch AC generator (84 or 86 amperes) are essentially the same design as those used with the dual-output AC generators (Figure 8-69). However, an engine controller replaces the separate logic and power modules