Ford Mustang Brake lights?

You are on the right track. There are two or three different fuses that will take out your brake lights. One fuse panel is located under your dash on the drivers side. When you locate it, there should be a cover with a fuse diagram printed on it. This will tell you where to look for the brake light fuse. Under the hood there is another fuse panel with larger fuses for the a/c and starter, etc...etc... Yes there is a fusible link in the hot wire feeding the entire brake and tail light assembly. It will be located either in the trunk, or under the carpet running along the drivers side of the car.

I am assuming that you have checked the bulbs and found them to be good. Also check the sockets that the bulbs mount in. Are they corroded? Does the bottom of the inside of each socket feel springy if you push on it? There should be some resistance but the bottom of the inside of each socket should give a little bit and then spring back to its original position. You pony being an '89 model, age deterioration should be a pertinent consideration. The fact that your cyclopes brake light is still working tells me that your brake switch mounted on the brake pedal arm is still in working order. I hope this helps you in your endeavor.

in case you have already checked the bulbs, i might say it is the activate yer brake pedal. maximum mechanics will basically charge you approximately 25-30 dollars to restoration it. or you could order the area yerself and dad it in.