I also have a 69 caravel and had a electrical problem. It was an
intermittent problem. Checked all fuses, wires, act. It turned out to be a
fuse in the fuse block in the univolt. Seems that the filament was loose on
the inside of the fuse. While it would read ok when tested cold it would
not connect later. Ended up pulling out all fuses and retested. Worked
several hours and much frustration. Good luck.