My ignition switch went out about the same time by blinkers stopped working, I don't know if they are related but I replaced both at the same time. However when I replaced my relay for the blinkers it wasn't fully connected so that may have been the problem. In my 85 the relay was under the dash on the left side of the steering wheel. :winks
Bad ignition switches cause this problem all the time. I checked my fuse, replaced the turn signal relay(the emergency flashers have a separate relay), and found one of my turn signal bulbs loose in it's socket. It was the ign. switch. Do a search, there will be plenty of information available if you need more examples.
Mine is a 92 and my relay was behind my glove box and was blue. Your signal relay may be silver? And may be close to the radio or behind your fuse panel(not sure). Like I said do a search, there's a lot of info. about this problem.
A forum community dedicated to Ford Mustang owners and enthusiasts. Come join the discussion about performance, builds, modifications, reviews, engine swaps, classifieds, troubleshooting, maintenance, and more!