1991 F-350 turn signal & overdrive shut off switch

[Shorty Thompson]

I borrowed a trailer to haul a car with . I used the turn signals at every turn , now the overdrive shut off switch doesn't work , and the turn signals don't work . I checked the fuse , it was blown , I replaced it and the flasher unit . No luck still neither are working . Is it possible that before the fuse blew out that it took the turn signal switch out ? Also are the 2 connected ? All replies will be very helpful.

Thanx