Got a chance this morning to closely examine the fuse block on my 64 Dart and wish now I hadn't. Noticed two slots were empty: Radio (it is a radio delete car anyway) and Accessories. The remaining slots had at least one badly rusted clamp (for lack of a better word) at one end. I gently removed the fuses and applied some DeOxit to the clamps. It was then that I noticed the clamp holding one end of the Heater fuse had slipped into the fuse box and was no longer visible to the naked eye. It wasn't a a rusted one; nice and shiny. Uh Oh! I am wondering if, in addition to now no longer having a heater that works, if that loose clamp is going to bite me via a shorted out fuse block somewhere in the future? I've never removed and replaced a fuse block before and the Service Manual Instruction to remove the screw mounting it under the dash is hardly adequate. I'm thinking I am going to have to replace the fuse block and I have no idea how to remove the wires connected to it, or where to buy a replacement. Can someone help me out? UPDATE: Upon the recommendation of a fellow TMC member, I partially removed the fuse block, pryed off the plastic top, and there was the clamp along with the wire attached to it completing the heater circuit. Simply pushed it back into the slot, put a fuse in so it wouldn't slip back into darkness, and life is good once more. I won the battle today and learned something also.