Ballast Resistor

I have a 73 340 Dart sport. It was originally a 318 car. I'm trying to determine if my issue is the ballast Resistor. Only problem is I see two. There is a white one with one connector on each end right next to the wiper motor. Then there is one on the corner of the firewall near the inner fender with two connectors on each end. Are there supposed to be two? Is one of them not a ballast resistor?