73 Fleetwood -Short in 25A lighter, interior lights fuse
 

Just got this car from across the country. 25A fuse shorting to ground. Popping in fresh fuse immediately burns out. Bought ECT3000 to troubleshoot and find short location. Help! Short seems to be coming from two locations, each with numerous conductors and large wire bundles. It's a wild goose chase! I haven't found any damaged wires. Car came 73 shop manual with electrical schematic. Doesn't help.

Issue was resolved.
 

After a few months, I came to realize the clock was shorted and caused the 25A fuse to pop every time. Wasted my money on a diagnostic tool that was difficult to use. Once the clock was disconnected, the fuse was fine and all interior lights worked. Wasted hours of my time. Lesson: disconnect clock first if interior light fuse keeps blowing.