Need brake light wiring diagram for 1983 AMC Concord

The power goes from the battery to the fuse box and then to the fuel pump relay, so just concentrate on the fuse box. Depends on vehicle and model whether fuse gets power anytime the battery is connected (hot at all times) or only when the key switch is in "on" (hot in run or start). You have a test light to check for power at the fuse terminals? That is how to start.
Some older models used "fusible links" in major circuits to distribute power, like to the fuse box, or to the ignition switch. The links act like fuses to protect wiring, they will "blow" or burn out if a big short or surge tries to damage wiring. Then you can just cut out and replace the fusible link. Nowadays, they mostly use maxi-fuses instead of fusible links, but you would need to consult a wiring diagram for your vehicle to really know the set up.

Check the starter connections for a corroded/blown fusible link.Pull on the wires attached there and if one pulls apart easily,it's defective.

https://s26.postimg.org/gukptsw7d/headlamps.jpg

Click on the link.
Usually on older vehicles, the headlamps don't use a fuse, but, fusible link, as shown in the diagram. Usually the park lamps and instrument cluster illumination are fuse protected, like the diagram shows, Not only check the fuses, use a test lite to check for voltage at fuse and at fusible link. The wires on top of switch in the diagram are voltage to headlamp switch, the wires on the bottom is voltage from head lamp switch to component.
Usually one of the wires from Battery positive goes to fusible links, at the moment, I don't have location.
Hope this helps, a little. I just want to add voltage and ground both are important.

Maybe power got cut going to the headlight switch. I think that would be a fusible link coming right off the battery source and going to the switch. Fusible links were used as power distributors before the era of maxi-fuses and power distribution boxes found in today's cars. Just like fuses, the link is designed to break and stop current flow if power demand is too high, like a short. Sometimes they get old and just give out. When the link goes, the wiring insulation may bubble or melt off some, the link may feel uneven or rough. Fusible links can be cut out and replaced with a similar rated new link. If you have no power to the headlight switch, look for a melted fusible link.

It may not be a fuse at all it sounds from the description (14a) it is a 14 gauge fusible link which is a wire that will burn out like a fuse, check for 12 volts with a multimeter or test light from the fuse box and then continue down the circuit until you cannot find power. Just before this point you should be able to see a part of the wire that looks different and that should be the fusible link.

How about fusible links. Got a wiring diagram?

There are a handful of fusible links on that year vehicle. A repair manual will give you a wiring diagram that should show what's not working with a "blown" link. From there, you can use a "loom diagram," which should also be in the repair manual, to locate the offending wire and replace it-- You don't need to replace with with another fusible link, but you do need to put a fuse that's rated with the same amp. value as the link should have been.

I have a 72 amx, the two wire conector at the brake light switch down on the brake pedal is light green and pink and the plastic connector is brown and plugs into the switch at the top of the brake pedal.

Any quality gasket from any parts store will work.