Subaru vacuum leak?

My 99 Subaru Legacy Outback has an issue w/ the air/vent/defroster selections. The lites sometimes don’t lite up and when that happens, the selection doesn’t work. It sounds like the fan is working but the air is not coming out. If it’s a vacuum leak, can I fix it by finding a leaky hose or is it an involved process? i.e.: professional

From what you say it sounds like the vent control is done electrically rather than with a vacuum system. There may be a loose connector causing the trouble.