Help! Sudden electrical problem

[VetteVet]

Start at the source, the battery cables, tight clean connections then the negative ground and the positive at the starter. BTW the positive ends at the starter no power will show at the solenoid until the key is turned to the start position.All positive power comes from the red wire stated above. The red wire feeds the key switch and the light switch, the horn relay and then the key switch feeds the fuse panel and the starter solenoid.

Speaking of grounds, my abttery grounds to one of the water pump bolts; is this normal? The cable and its ends look original.

The negative battery cable can be bolted to any good ground point on the engine, but remember, the engine is rubber mounted so it needs to be grounded to the cab and the frame to complete the electrical circuits. IIRC there are 5 ground straps on our trucks to complete all circuits.