Why the Brake lights go permanently on when just the light switch on?

Tiny
LANDOROS
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  • 1996 TOYOTA COROLLA
The brake pedal switch is working right as well as the light switch. If I take the "stop" fuse out, the brake lights still remain on but if I put it back and take the "tail" fuse out instead, the brake lights work as they are supposed to but then I don't have tail lights. I guess because I'm not good at electrical circuits and/or reading blueprints, I can't figure out what's going on. Please help !. Thank you.
Wednesday, January 11th, 2012 AT 3:07 AM

12 Replies

Tiny
FIXITMR
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Did you change the brake switch or anything else when this started to occur?
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Wednesday, January 11th, 2012 AT 3:09 AM
Tiny
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No, I didn't change anything. Weeks before, the clockspring got broken so the car was without cruise control, horn and air bags.
I already replaced the clokspring so those three functions are normal now but the brake lights are still on.
Even thou I knew the brake light switch was good, two days ago I boguht a new one just to be sure and sure enough it was to no avail cause the lights were still on, so I returned the switch and put back the old one.
The way it works when I pull the "tail" fuse out doesn't give you a hint or a clue about what's going on?
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Wednesday, January 11th, 2012 AT 3:46 AM
Tiny
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Somebody out there. Any answers. Any HELP!
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Wednesday, January 11th, 2012 AT 2:03 PM
Tiny
KHLOW2008
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You sure it is the brake lights that is staying on or is it the taillight that is not turnng off?

Check for a bad ground wire at taillight and a faulty taillight relay or switch.
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Wednesday, January 11th, 2012 AT 6:28 PM
Tiny
FIXITMR
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Did you do CS repair before this tail light issue came up? Obviously the signal for tail light is bleeding into brake light circuit. So the question is where is this occurring and what caused it. If the turn signals use same bulb as brakes the column work could have something to do with it.
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Wednesday, January 11th, 2012 AT 6:44 PM
Tiny
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For KHLow2008: I'm absolutely positive, 200% sure it is the brake light always ON when the light switch is on, if I turn the light switch off, everything goes off but the brake lights doesn't have to turn ON just because I turn the light switch ON.
Is there any tail light relay, where is it located in a Toyota Corolla 1996?

For fixitmr: As I said in the beginning, I repaired the CS way after the BRAKE light issue came up. The turn signals don't use the same bulb with the brakes. The brake bulbs are the same as the tail lights (two filaments, one for tail light and two for brakes.
I have noticed that this malfunction is turning on and off on itself. Sometimes it starts after applying the brakes, another times just by turning the light switch ON and also sometimes turns off whenever it wants. I guess what you said: "obviously the signal for tail light is bleeding into brake light circuit. So the question is where is this occurring and what caused it." Is the million dollar question but I have no clue as to where it's occurring or what caused it. It's really crazy, please help, I already got a warning from a cop.
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Wednesday, January 11th, 2012 AT 9:17 PM
Tiny
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Actually I shoulda asked if brake and tailight bulb are same bulb! My thinking was backwards associating column work with possible bulb conflict.
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Thursday, January 12th, 2012 AT 1:49 AM
Tiny
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Another thing, when this happens take a bulb out and check for continuity between the 2 contacts. If there is then that confirms source of crossover juice.
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Thursday, January 12th, 2012 AT 2:11 AM
Tiny
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Could be a screw got put thru the harness somewhere and finally made short.
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Thursday, January 12th, 2012 AT 2:12 AM
Tiny
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Sorry, do you mean continuity between the 2 contacts of the socket. How must this check be done?
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Thursday, January 12th, 2012 AT 2:53 AM
Tiny
KHLOW2008
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If the brake lights comes on when the taillights are turned on, that can only mean a bad ground wire connection at the taillights. The taillights are back flowing through the brake circuit causing them to turn on.

Have you checked the ground circuit at the taillights?

Since removing the the taillight fuse stops the lights from coming on, I would suspect an intermittently sticking tailight relay, located in junction box # 1, at left kick panel.
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Thursday, January 12th, 2012 AT 2:46 PM
Tiny
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In this case with 12v I use pocket test light.
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Thursday, January 12th, 2012 AT 8:32 PM

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