Most, if not all, of the Sunbeam’s electrical parts were manufactured by Lucas electrics. I don’t know much about the company, other than the joke about Lucas, prince of darkness. So far, I would like to report that the nickname is groundless, but I am finding that the Sunbeam’s main problem is that the parts are groundless.
Below you can see the bottom of the car with a few wires hanging down. I have no idea what they are for, but I do know that they are (were) hot. If you look carefully toward the top of the picture, you can see the wires touching the exhaust. When test running the engine, the insulation melted and sparks began to fly. Solution? The wires carried 12 volts with the ignition on, but it was not obvious where they were originally
connected. The wiring diagram gave no clues, and I am still looking.
Repairing the turn signal and stop lights involved removing corrosion and installing new bulbs in almost every socket. I also replaced one socket that was cracked. With these simple repairs, I had working lights, but they were dim. Perhaps they were up to standards in the 1960s, but not good enough for today’s roads.
My solution involved two steps. On most lights, I soldered a ground wire to the bulb socket itself and then connected this to the body. Below you can see a thin black wire with one end soldered on the socket and the other end crimped into a eyelet connector. This is connected directly to the body.
Second, I used modern LED lights for increased brightness. I think this helps, but I am not sure. In any case, the exterior lights are now bright enough.
At some point, I think I will replace the Sunbeam’s wiring system. Although all of the wires seem to be in good condition, I am concerned that the system was designed with only two fuses and no relays. Perhaps in the fall when the weather is better, I will buy a modern harness.
Just below is the fuse block. You can see the two fuses running horizontally in the middle of the picture. At this point, I have added two circuits, the fuel pump (reddish connector and black wire on the right) and the electric fan (red wire and translucent connector on the left). The fan is connected through a temperature controlled relay. The fuel pump does not have a relay, but I’ve added an inertia switch in the circuit that turns off power to the fuel pump in case of an accident.
Sunbeam 