Abstract: A 3-module electrical connector custom assembled for specific applications by mating together a central module and first and second contact modules to form an insulative housing for electrical contacts. The central module has a single row of contact receptacles for housing electrical ground, voltage or signal contacts. The first and second contact modules are selected from a group of preformed contact modules having configurations of from one to three rows. By proper selection of the first and second contact modules, a 3-module electrical connector can be custom assembled to have a predetermined number of rows of contact receptacles. The total number of contact rows can be odd or even numbered, and can be symmetrical or asymmetrical with respect to the single row of contact receptacles of the central module. The 3-module electrical connector can be used for insertion mounting of the terminal portions of the electrical contacts in corresponding holes of a printed circuit board.