I had this problem on a new auto, used a bit of electrical tape to reduce flow. If I understand correctly, the new batteries are designed to accommodate the new premium carts - which have a lower impedance coil, therefore burn hotter (giving better performance), but then require more air flow to cool the coil to prevent singing. The vacuum switch in the auto's was probably not redesigned however, and those switches that are slightly out of tolerance on the "stiff" side, may not be activating due to the lower vacuum pressure resulting from increased air flow through the larger battery holes. I am hoping V4L will refine the design and manufacturing tolerances to take care of the problem, but until then, I find myself using my manuals more frequently. My older autos with the smaller battery holes seem to work well, but guess what, the premium carts burn hotter.
For Adrenalynn, get out your transport phenomena and two-phase heat exchange textbooks, lets crunch some numbers
For Adrenalynn, get out your transport phenomena and two-phase heat exchange textbooks, lets crunch some numbers