Ford F-53 chassis has a problem with a connector at the base of the steering column tilt mechanism. The first thing I had to have done was a repair of that connector. Luckily, I bought an extended warranty, so it only cost me the $100 deductible. On mine, the lights worked fine when the tilt wheel was all the way up, but when I put it down to driving position, no turn signals.
Try that and see what happens. If the lights work when the wheel is all the way up, but not when down, I would bet on that connector being messed up.
Good luck.