Page "Apollo 16" Paragraph 31
After landing, Young and Duke began powering down some of the LM's systems to conserve battery power.
Upon completing their initial adjustments, the pair configured Orion for their three-day stay on the lunar surface, removed their spacesuits and took initial geological observations of the immediate landing site.
The landing delay caused by the malfunction in the Command / Service Module's main engine necessitated significant modifications to the mission schedule.
Apollo 16 would spend one less day in lunar orbit after surface exploration had been completed to afford the crew contingency time to compensate for any further problems and to conserve expendables.
In order to improve Young's and Duke's sleep schedule, the third and final moonwalk of the mission was trimmed from seven hours to five.