05-28-2013, 06:11 AM
Forest, I'll respond for Steve. For many years, foreign cars have separate lights for the turn signals, and American cars incorporated the turn signal in the brake lights. Now, most American cars have adopted the foreign system, including Newell. Typical trailer lights and tow vehicle lights usually incorporate the American system, which is simpler and requires fewer wires. Thus the need for a diode system to make the conversion.
2001 Newell #579
tow a Honda Odyssey
fun car: 1935 Mercedes 500K replica