Sounds like crossed wires at the ammeter to me as well.
I don't have a '47 wiring diagram, but I do have one for a '50 Chevrolet truck. Assuming the two are close to the same and that your wiring is stock .....
The + side of the ammeter should have two wires attached. One comes from the stud on the stomp starter switch. The other goes to one terminal on the horn.
The - side of the ammeter feeds the rest of the truck.
Do you KNOW the generator is charging when the engine is running? Quick test: Start the truck and let it idle with the headlights on at night. Have a helper rev the engine. Did the lights get brighter??
Last edited by Bill Hanlon; 06/26/2024 10:19 PM.
'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.
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