Towbar electrics

Not a good a good day today,just went to pick up the van for a wash and get it ready to go away for the first trip of the season and my car does not detect the caravan!!!!! spent 3 hrs stripping down both ends cleaning and making sure everything was where it should be but still nothing!!!!!.

Has anyone out there had issues with Q7 electrics,this is my second Q7 and never had issues before im due to go away on Monday but not sure if i can get it booked in before then for a pro to look at it.

thanks