Son in Atl Trying to get 99 mustang through GA inspection and hazards don't work but blinkers do. Any thoughts on first places to start I can pass on to him.
I would tend to believe it is the multi-function switch located inside the steering column attached to t he turnsignal lever. It controls all 4, hazards, wipers, blinkers, headlight flash to pass-high beam. Everything goes through that switch and I have read on many occassions that this is a common issue with Ford. In this first diagram the turnsignal arm is attached to the switch mounted to the column, the 3 plugs shown below is what plugs into the switch. Those are what needs to be inspected, corrosion, melting, or pin pulled out, if all that is good, then I would recommend replacing the switch itself. Any Ford dealer should have it relatively on the cheap. In the 3rd pic shows the pins for the hazards and turnsignal and headlight flash to pass-high beam.
The switch is easy to get to and take off, but have your son look and inspect the contacts and plugs going into this switch. I have seen the mail end of the plug, there is like 3-4 of them going into this switch, literally melt and turn brown, I have seen the pins corrode and just need cleaning, and I have seen the pins pulled out of the pigtails. So make sure your son inspects the switch and the 3- or 4 plugs going into the switch. Oh and welcome to the site.