Volvo Repair: intermittent headlamp, volvo vadis, vadis system

Question
Hi Roger,
My daughter has a 2003 Volvo V70 XC AWD wagon. She will have one or the other or one time, both headlamps go off for up to an hour then come back on. The shop wants to replace the wiring harness. I think they just want to cover themselves. To me it seems like a relay module, but I have no wiring diagram to check it out. Can you help?
Thanks,

Jerry

Answer
Jerry, could be a module.  Is the car at the Volvo Dealer?  If not, better get it there.  That car is computer controlled. If it has under 50K miles, its still under warranty.  Dont let Non Volvo techs mess with your car.  It has sensitive electronics and requires the Volvo VADIS system to perform diagnostics.  Roger