Tobias,

It's always best to specify the year and model when asking technical questions. I'm going to assume you have a pre-85 non-Westy Vanagon. If the guess is correct, those wires will be for the rear speakers which are apparently missing from your van. 

Regards,

BenT
sent from my electronic leash

On Jun 10, 2011, at 11:05 AM, Tobias Gogolin <usertogo@GMAIL.COM> wrote:

> Hello fellow Vanners!
> I have these cables sticking out from my rear ceiling close to the rear
> window, right side is red and gray, left is blue and gray, I don't even know
> what was mounted there, but I don't find these wires where the radio is
> supposed to be. I'm not much into audio other than bird song, but I want to
> mount an LED light and a little fan so I would like some hints on where to
> find these wires in the front!
> 
> Thanks
> Tobias