Side lights are normally 5w
You'll need a 3w resistor. About 48-68 ohm
Or find a friendly bmw centre to reprogram your ecu to the led resistance.
Putting load resistors sort of negates the low power Useage of LEDS as you are still consuming the same power as a normal filament bulb.
Thanks Mark, I'll see what I can find in Maplin.
You are right, putting a load resistor in parallel does negate the low power drain of LEDs but I'm more concerned about the visibility of the parked car.
I've also discovered that like a BMW the parking lights are controlled by the indicator stalk, you can't just leave the car with the side lights on. You have to select a side to illuminate!
Electronically it is more of a BMW than a Morgan. I don't mean that in a negative way, either.