To put the final steps of his plan into action ahead of the final battle, Mr. House requires the player character to go to the El Dorado substation and install an override chip that will give him access to the regional power grid and provide the opportunity to jump-start the Lucky 38's independent power system, ensuring that all the power produced by Hoover Dam will be redirected as he desires without issue.
The substation resides northwest of HELIOS One adjacent to the El Dorado Dry Lake. Upon arrival, it will be occupied by NCR troopers who will warn the player character not to enter; this is required to complete the quest, so there's no avoiding it. Entering in view of the troopers will turn them hostile, so one can kill them, or use either a Stealth Boy or NCR faction armor to enter the substation. Go and use the terminal on the far wall to install the chip (incurring NCR infamy), then exit the substation then and return to Mr. House in the Lucky 38, triggering The House Always Wins VIII.
Quest stages[]
Part VII
Stage
Status
Description
76
Go to the El Dorado Substation and install the override module.
