I have a 1993 Mazda Protege. When I turn the running lights and/or headlights on the brake lights seem to turn on as well. All three lights come on, the two rear lights and spoiler light. However, when I press the brakes the lights do get a bit brighter. Does anyone know why this is happening?
Possibly a defective bulb. Sometimes with age and heat one of the filaments in a dual filament bulb will sag and make contact with the other filament. This will then illuminate the whole thing.
You may have a grounding problem. If a ground wire in the back is broken the lights can act funky in the back. You’ll have search for a common ground. Usually not hard to find.
An electrical short from the running lights wire(s) to the brake lighs wire, is the cause. Check, particularly, under the dash where your footsie many have kicked the wires.
Ok, thanks…so could you explain a little more what I would be looking for? Like would the wires be worn or what? They seem to be all tightly wrapped and out of the way.
I had a trailer with a similar problem, I ended up replacing the light assembly even though everything looked good, then it was fine, It was almost like it was haunted but there was some internal short or something going on. To narrow down the problem you might try removing a bulb at a time, seeing how things work, replace the bulb and try another. Hopefully that will give you a problem socket or bulb.