This handy little adapter harness allows you to plug an oval 4 pin late model GM alternator in to a Rectangular CS130 or CS144 vehicle harness. This harness is required in order to install certain high output alternators on GM trucks that originally came with a CS130 or CS144 alternator with a rectangular plug from the factory. This is common on most 1988-1995 GM trucks, as well as some later models equipped with the heavy duty charging option.
This is similar to our H101 harness used on 240 amp part numbers that do NOT require the 12v switched wire activation. All 250+ amp Denso style upgrades will REQUIRE the 12v switched lead to turn the alternator on and off.