Volvos are famous for fuse panel problems... Check fuses & their connections first... Signals are fused on different circuit . IF fuse ok... Suspect hazzard switch .. Have a look at this link, below:
http://www.ebay.com/ulk/itm/121793224883
RepairPal Certified shops can diagnose and repair your 1993 Volvo 850. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.