Most likely the left tail light ground wire is either damaged, disconnected or the body contact point is rusted to the extent that it isn't making connection.
short in the wire or they are all on one wire
the parking brake may be stuck and that causes the brakes to lock up completely, and the horn and lights will stick work if the parking brake is stuck.
Possible malfunction with the alarm. Thats if the car has an alarm (mine doesnt) Could be a possible defect with the light switch itself which also opperates the parking lights.
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.
"cross grounding" is caused when stuff in the trunk damages a ground wire, or the wrong bulbs are installed... or the sockets where the bulbs plug in are messed up also see if your local library has a free professional shop manual to look at... dave
The most common cause is a broken or corroded ground wire.
Check the fuse for parking/tailights (dash lights also on this circuit)
Headlights, interior lights, parking lights,Headlights, interior lights, parking lights,
Brake and parking lights? Are you sure, the two aren't interconnected. Maybe it's just the brake light. If so, sounds like a bad brake light switch. If you step on the brakes and the brake and parking (sometimes called running lights) lights come on it sounds like you have a real problem. Suggest you have it checked right away.
The parking brake and parking lights begin with P.Other bits are the passenger seat, pedal, piston, power brakes, power steering and the power window switch.
If you pull the parking brake up the running lights will go off - if not - start the car with the parking brake on and that should work, if you want to drive with the running lights off - you can get away with "slightly" putting the parking brake on (just so the parking brake light goes on in the dash but the brakes itself makes no contact) Otherwise you can remove the relay that controls the daytimes - maybe even a fuse
The parking lights are turned on when the headlights are on and you pull out on the light switch. The parking lights cannot be turned on by themselves.