On my car the a/c blows cold out of the center vents and mild temp out of the side vents. I checked the vaccume going to the heater valve in the cowl area, and it isnt getting any vaccume. I traced the vaccume line to cab and underneath the dash on the passenger side into a box, it had another vaccume line going to it, i tested it and it has vaccume. To get by for the time being, I ran a vaccume line from the main vaccume source to my heater valve and it is closing completely but the side vents still do not blow cold. I would like to fix, I dont know what is wrong, can anyone help?