I had a ballast resister which failed intermittently before it completely failed. It would test good on the side of the road, but would lose voltage going down the road (bumps, vibration). Jumped it with the wire with alligator clips, and down the road I went.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission