Your question is TOO vague Sounds like you have DRL's Daytime Runing Lamps Try turning the light switch on
In the back should be tail lights which always come on when the headlights or parking lights are on, and stoplights which come on whenever the brakes are pressed. The stoplights should be brighter than the tail lights, but they should be separate.
First, check the tail lights. Turn on the headlights and see if the tail lights come on at the same time. If the tail lights come on but the dash lights don't, it's probably either the switch or the bulbs. If NEITHER come on, it could be the switch, the fuse and of course, still the bulbs.
Check your fuse for tail lights. I think the dash and tail lights are on the same fuse so you know when your tail lights don't work. Might have a short or an open in that circuit.
The headlights and the tail lights may not be working on the 1981 El Camino because of a mechanical breakdown.
First check the bulbs then check the fuses.
If your headlights work, but your tail lights don't, your bulbs could be blown. It is possible that you have a shortage in your car.
one of two things, BAD EARTH, or Relay switch.
check the fuses - there is no fuse for the headlights.
The brake lights should not come one until you step on the brakes. The tail lights should come on when the headlights are on. If they're weak, maybe there's dirt in/on the lenses or maybe the bulb is old and clouded. Change the bulbs and see if that improves things.
Most likely a fuse.
Brake lights should NOT be effected by the headlights. Brake light function is completely independent of the headlights. Assuming you are not refering to the tail lights, or marker lights, which are supposed to come when the head lights are turned on. Not having brake lights when the head lights are on is a big safety problem and should be corrected.
In that case, you probably don't have tail lights or clearance lights either.Check the fuses. If that's not it, you may have a faulty light switch.