Hi, folks. I've been having a devil of a time getting my blinkers to work on my 76 fj40. The hazards work, but not very brightly up front; the blinkers don't work at all anywhere. I *think* I have ruled out the fuse, fuse panel, relay can, and switch. I read on line that the turn signals on the fender are supposed to be dual filament, at least for the big yellow front ones. Mine are single filament. Is it true that they are supposed to be dual filament, and that having singles could be the source of my problem?