66 Valiant heat/ac fan question

O.K., I checked all the wiring and everything's plugged in where it goes, but it's blowing the heater fuse. I'm going to pull the fuse box and look behind it to make sure nothing's shorting it out...Does anybody have any idea of what else runs off of the heater /ac fuse? I'm looking at some schematics here but they're incomplete and only show partial wiring for the heater controls. I'm getting my 12V at one side of the fuse holder, but it blows a fuse everytime you try to bridge it through to the system. Thanks in advance!