Inertia switch

A lot of Fords utilize an inertia switch but I can not find one listed as a replacement part for your truck. I don't think they were used thirty three years ago. If you are asking because your fuel pump doesn't run, you should check the fuel pump fuse and the relay. You can also test for voltage at the pump, or direct wire the pump to see it run.

Now we know where to look for that inertia switch, so please post that Ford part number when you find it so I can Google an image.

I found something called a "fuel shut off switch" but I wasn't thinking you have to crash into a solid object to make it work. That's where the "inertia" part comes in.