You could use a resistor placed on the light blue wire of relay R1 to ground but it would need to be a pretty big power resistor. The resistance would need to be around 6 ohms and the wattage would need to be 38W or more. A better solution is to use a relay. Here's a
circuit showing how to connect relay R4.
You don't need to use the same type of relay as used in the original headlight door circuit. Any standard 12V automotive relay will work.