I have a 2000 accord coupe EX.And i was in a rear end collision, I took it to a body shop to get it fixed and 3 weeks later my head lights/tail lights stop working. But the turn signals and hazards works. I checked the fuses and they are fine. However the wires that leads to the right light were burnt. I replaced those 4 mainwires, 2 were not leading to anything. and still no luck any suggestions?

 

There's often wires that go nowhere, just for options that you might not have installed. Brake lamp in a trunk spoiler? Of if it's in front, maybe those are foglight wires?

 

I followed those 2 wires and they led to nothing so i unplugged. I dont understand how the brake lights and hazards works but the tail light doesn't

 

There are two sides to a circuit to get a bulb to turn on, voltage and ground. What wire colors are the two that are not plugged into anything?

Most ground wires are black. The voltage wire for the all the brake lights is the wht/blk wire. The tail lights is red/blk wire.

You need to figure out if you are missing voltage or ground at the bulb socket(s) that are not working.

If you have a volt meter test for voltage between the red/blk wire and body ground (any bare metal bolt will work for a ground). You can also test for continuity (~ zero resistance) to ground on the blk wire at the bulb socket.

 

There's a small black and a small red wire that leads to nothing on one end. but on the other end they leads to a thicker red and thicker black. To my knowledge they were never hooked up. Could this be a problem due to the multiplexer because the tail/dash light doesn't turn on at all.