There is a translucent vacuum line that goes from the pump to a vacuum manifold under the hood that helps the engine vacuum keep all of the A/C vacuum elements working. IF you have a leak in the A/C system, the vacuum pump will run as you described that yours is running.
Try pushing the EC button with the temp set at 72deg & see if the pump stops running. IF so then the fresh air vacuum element is leaking!! Good luck.

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