my blower motor delays on AC or Vent when accerating, it will restart when I totally let off the gas

This is a 1996 E150. I could only find 1 line that runs behind the blower motor housing,and didn't hear hissing.

ok,i understand it's a van.copy and paste this link,watch the 1st and 2nd video.check that panel on top also.see if you find anything............................................................................................................................................... Ford E350 AC Repair: stops blowing through … www.youtube.com/watch?v=Q_ONYTRi26A