Fitting a Shark Fin!

[AndyZebra]

Can somebody help? I’m in the process of fitting a new shark fin to the boot lid of our 2012 E220 Cabriolet. The old one has given up due to water ingress. The new fin has arrived but with only one lead connected and the current one has two attached... I’ve checked the part numbers and they differ. However my ‘friend’ at our local dealer assured me it would be correct. Can anyone throw some light on what the two cables are for that are in use, one is tagged yellow the other purple.