Alternator & Regulator: Description
Delco-Remy CS charging system uses the Delco-Remy CS-121 and Bosch CS-130 alternators with an internal voltage regulator. The only difference between the Bosch and the Delco-Remy alternator is the harness connector design. The Bosch alternator has a single blade harness connector, while the Delco-Remy alternator has a 4-cavity harness connector.
Alternators are equipped with internal regulators, delta stator, rectifier bridge, and rotor slip rings and brushes. No test hole is provided. Some late model production vehicles using the Delco-Remy CS-121 alternator are equipped with Generator Inverting Buffer (GIB) module. The GIB module is located near the fuse block, below the left side of dash. The GIB is connected in parallel to the charge indicator light. The GIB module turns off the A/C system and the rear window defogger should alternator output drop below a certain level.
The CS-121 alternator requires only 2 connections, battery positive and an "L" terminal to the charge indicator bulb. Use of "P", "I" and "S" terminals is optional. The "P" terminal is connected to the stator and may be connected externally to a tachometer or other devices.