speed sensor wire

[Stu_c]

I need to find the speed sensor wire for my new head unit, i think there must be one as my orignal radio goes quieter and louder with the speed of the car anyone know what colour is it on a mk4 2002 golf?

thanks

[Froggy]

It should be the one that is marked gala on the original loom. (See diagram on top of original radio)