Vacuum motor noise in HVAC system

[RTRAM]

I have a 1993 CTD and I hve started to get a whistling sound from under the dash. I changes with the different HVAC selection. '



Is it the vacuum motor? If so, how do I replace it? How hard is it to get parts? Thanks

 

[DVolk]

Id look for a vaccume leak probally buy the diaphram that works the vent door