tow bar wiring conundrum
 

Just bought an xc70 , garage put a new tow bar and electrics on for me ..when I connect the caravan to the car the caravan lights flash once and go off also turn off the rear n/s lights on the car ..remove caravan plug switch car lights on and they are working again.....cleaned the caravan plug connections but to no avail ,,,any ideas anyone,,going away on Saturday.

Best get it back to them or to a volvo dealer for a quick fix with genuine parts ...

Did they use the genuine Volvo ecltrical system that just plugs onto the vehicle electrics? It will need a software update to work completely but should work all the lights without the software. The software switches off the rear fogs when the van is attached, checks the lights are working and modifies the Traction control to work with the caravan in the event of snaking starting.

From what you describe they did not and have cobbled together a system that clearly does not work. Take it back and get them to fix it.

indicator lights
 

the caravan indicator lights work !! and on the car