The coil wires, if original, are made of solid copper and rarely go bad.
It is always recommended to change the three coil wire resistor ends.
They are $7-$10 each, depending on where you buy them.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".