No Power in the car, but there is in the engine bay

Actually I didn't intend for the OP to jump into a bypass project. What was in my head is the simplified diagram that shows how the main power is distributed. If you have "no power" it is almost always related to battery connections/ cables, the fuse link, bulkhead connector, or ammeter connections. "In rare cases" ------hey it's happened-------the "welded splice"

This is the simplified diagram of the FACTORY wiring

View attachment 1715096411

Follow along the "functional path" NOT "electron flow." From the battery, depending on year, the power "arrives" at the big stud on the STARTER RELAY.........From there through the FUSE LINK........through the BULKHEAD (RED) and to the AMMETER.........through the ammeter and out on the BLACK ammeter wire and to the WELDED SPLICE. (This splice is a few inches from the ammeter up under the dash)...............

From there things branch off various years / models......

to HEADLIGHT SWITCH
to FUSE PANEL HOT BUSS
to IGNITION SWITCH

If none of this is working, start at the fuse link, follow it to the terminal in the bulkhead connector. Use a meter or test light, you have power there at the bulkhead connector?

Yes? Then reach up under the dash and feel and find the ammeter wires, and with "something on" (like the dome or headlights) wiggle the ammeter connections, are they loose? Spark? Power comes and goes?

If not, then pull your bulkhead connector apart, inspect, repair, etc

DO NOT GET LED down the wrong path!!! With all power "off" and IF YOU DO have power at the bulkhead connector, this may be an erroneous "reading" due to a POOR/ INTERMITTENT connection. Turn on the headlights and see if that "goes away."