I don't have a 1946 Chevy truck wiring diagram, but both 1945 and 1950 diagrams have only the starter motor and the horn not going through the ammeter. Properly wired, any other electrical load should cause the ammeter to show additional discharge. Might be hard to see if the engine is running.


'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.