hello

anyone know what this line is for? I have codes 25 and 71 to diagnose. i drove the truck about 90 miles to its new home with no problems. i changed the oil and added some seafoam to the fuel pior. i guessing some codes were cleared prior inspecting the vehicle??? Shop manuals have been ordered but shipping has been delayed due to the holiday.

any suggestions are greatly appreciated!

 

As best I can tell from your photo, that goes to the vacuum reserve tank inside the fender. The reserve is used for the A.D.D. switching. https://web.archive.org/web/20120424...26addcontr.pdf