What this valve/vacuum hose on the firewall. I guess its time for another retarded question. '82 K5 w/350 and newer 700R4 (? on the tranny year, the guy before changed everything and the tranny has one of the big GM stickers with the bar code and big letters they but on there new stuff on the side of the case). Anyways, near the wiper is some electrical wires that lead into a valve which has vac line comming out with a little light blue and black cylinder inline of the hose. What is it? It isnt hooked up, where does go? My vac routing is basically a copy of 1969-75, if that helps for hooking it up again.