Assemble body for Skynet

Assemble body for Skynet is an unmarked quest in Fallout 2.

Detailed walkthrough
The Chosen One discovers this quest on the third floor, by talking with Skynet's mainframe. (Be sure not to lie to it.) To discover the pieces necessary to help, go to the next room past the door to the room with the mainframe, to a room with an inactive robobrain and a nearby computer terminal. Conduct a system check with the computer terminal to determine the needed pieces.

All pieces for Skynet can be found at the Sierra Army Depot. The bio med gel is on the floor just above and to the right of the robobrain. You can get a robot motivator from one of the robobrains, by killing one and taking it off its body. There are plenty on the second floor, but the fight could be problematic for an inexperienced Chosen One (alternatively, there's one motivator in the Navarro base, in a container in the vertibird hangar -- but that motivator might not function in some versions of the Fallout 2). Thirdly, Skynet needs a brain. On the fourth floor, retrieve a brain from the storage system, and the system will go critical, depending on the Chosen One's Science skill a brain can be saved, these are the abnormal brain, chimpanzee brain, human brain (90%), and cybernetic brain (121%), with the cybernetic brain being the best and the abnormal brain being the worst (remember that you can change the difficulty in the game on the fly, and there are a few Big Books of Science around the base as well). The quality of the brain used will determine Skynet's skills in combat.

Take these three things and go to the room just beyond Skynet's mainframe, where you will find an inactive robobrain. Fill it with the bio med gel, and install the brain and motor. Then activate the system via the nearby computer console, and the robot will come online.

Reward
Skynet will join the Chosen One as an non-player character at this point, assuming they have room.