2001 hyundai elantra brake lights not coming on checked fuse is good bulbs look good what could it be

check the tail light bulbs before you stert getting technical its only hyundai and their fairly simple to sort out

CK the wires on bulb sockets for a loose or dirty ground wire.

brake lights and blinkers use the sale filament in the bulb
the running light is the other (in a dual filament bulb)
you may have a poor connection or a break inside the bulb base.
test with a known good bulb.
the next place to look is the connector on the light switch and the joint where the running lights split off.

remove wires from switch and bridge them , and check if brake lights come on, if so switch is faulty ( assuming bulbs are ok)

could be wiring or a bulb filament
check bulbs

with brake lights, there are many possibilities.
first check the fuses. look at your owner's manual for the location of the fuse box. also,
for the brake lights, there's usually a switch built into the back side of the brake pedal. these can become loose , get unplugged or even just wear out.of course, they could be burned out. by front lights, i assume you mean headlights. either way, once again check the fuses, also check the bulbs themselves. if none of this works and you are having this much trouble with the electrical system, you might want to take it to a tech.

The brake sensor switch is located on the brake pedal. If fuses and bulbs are ok it should be the switch.

There are three mounting nuts on each lens assy which are accessed from the trunk behind the liner.

You either have a 'single filament' bulb installed in a 'dual filament' brake lamp socket ... OR .. you have a 'dual filament' bulb short circuited internally. Check your rear brake lamp bulbs (supposed to be 'dual filament' - two contacts on their bottoms). When you step on the brake pedal, do your dash lights LIGHT UP? A 'cross circuit' exists between brake lamp circuit and parking lamps circuit.

it could be related the connector cables thats bridging your lights and your brakes????