Whistling sound in 1992 Astro Van

Over the past month the van has started making a whistling sound. It is intermittent, sometimes soft and othertimes extremely loud. It seems to shut of momentarily when I accelerate. although not always. It is not the belt and not the brakes. We believe it must be a vacuum line leak, but which one of dozens?



We removed the inside engine cover and wiggled connections to be sure they were tight. When I drove the van the next morning I had lost my speedometer, odometer, gas gauge and battery gauge. We replaced a 20 amp fuse and now they all work. It seems too much of a coincidence that the fuse blew immediately after we started wiggling vacuum lines. Does the blown fuse give a clue as to which lines are most likely the problem? or is the whistle not a vacuum line?