1967 Cadillac Deville electical

You have the same problem I have, sort of. Its a crossed-wire problem; no doubt, they're on the same fuse.

My issue is with my 68 Sedan de Ville: the interior lights and engine temp warning lights are on the same fuse, and sometimes the interior lights stay on all the time after shutting the door, while other times the interior lights are never on, but the engine temp light is burning.

So, question for the experts: Is there an "easy" way to find out which is the faulty wire?

Its easy to reach the back of the fuse box from the engine bay. I can see where all the wires go into the fuses. Some wires' insulation are noticeably worn.

Problem is, the plugs are tight and I don't have the skills or tools to confidently unplug them and check for crossed wires. (Maybe they CAN'T be unplugged?)

ANY suggestions out there?

C'mon guys! Isn' there anyone who likes to dive under the hood of the oldies around here? I haven't found a 60s question that's gotten an answer on this forum. Surely someone respects the "Standard of the World?"