brake light won't turn off

[chieuvo]

240sx. brake lights always on and battery runs out quickly, I took out the master fuse to turn off those lights but still drains the battery after 1 hr. please help. thank you

[gumby74]

You may have to get into an awkward position. Pop your head under the dash and feel your way up the brake pedal. About half way up there is going to be a small ear with a hole in it. There will be a pushbutton type sensor that is supposed to get pressed in when the pedal is not depressed. You can either JB Weld a coin to cover this hole or run a small 10mm bolt and nut through the hole.

If this sounds complicated, pop your head under the dash and if you can see the sensor, it will all make sense.

[locoluna825]

my friend who recently just purchased a 240sx has the same problem but i wormed up under the dash and checked the switches and they have no affect on the lights staying on i even replaced them with mine, and they still stayed on.

why would you jb weld a coin to it? there adjustable all you have to do is back the bolt off and turn it till its in the right position.

[moso]

thats a honda thing, the hole used to hold a small rubber bumper that would press the switch for you, sometime its beyond the adjustment range. the best way i could think of to do this is to...charge the battery and while your friend stands at the back of the car looking at the brakelights begin removing fuses one at a time until thay go out. then at least you will know what circuit thay are getting power from. after that you should be able to figure out where that circuit goes.

[locoluna825]

yea his are trippin me out if you take the fuse out they turn off you put it back in they turn on we ripped the driver seat out and the bottom, of the dash, the carpet, the rear hatch plastics and cant find anything wrong with the wiring the only thing i noticed is someone nipped the hatch brake light at the body where the whole is. oh and i also uplugged his brake light switch at the peddle and they still stay on
Modified by locoluna825 at 10:27 PM 8/22/2009

[moso]

download the FSM, check out the schematics for the brake light system thay are pretty simple. get a multimeter. have fun.

[OutToWinPAHC]

Rubber boot fell of the switch on the pedal. Switch is located on the top of the pedal.

[locoluna825]

what rubber boot?

[gumby74]

The one I suggested you replace with a coin or small bolt.

There is nothing wrong with the sensor. There is no adjustment to be made. The sensor is doing what it is supposed to do.

The problem is the small rubber grommet that PRESSES THE BUTTON on the switch is no longer there. So when you press on the brake pedal, there is nothing there to activate the switch. The button is not being pressed in by the brake pedal anymore. You don't know me, but have a little confidence in what I am saying. Pop your head up under the dash, you will see the small ear sticking off to the side of the brake pedal. You will see the small hole I am refering to. You will see the small pushbutton type switch mentioned, and you will quickly figure out what I am saying. Weld on a coin or washer, or thread in a small 10mm bolt with a nut.

Stop messing with your fuses.

[locoluna825]

lol i looked on my 240 his 240 and the 240 in my back yard and none of them have this rubber thing yoru talking about, mine works fine and the one in the back yard worked fine. its only his that doesn't, besides if i press the button with my finger all the way in they still don't turn off.

[moso]

pull the switch out, stick a multimeter in both wires, if both are hot you know the line going from the switch to the lights is getting juice elsewhere. trace the line, find the problem.

[locoluna825]

if the button is constantly being pressed on while the pedal is up and untouched and the brake lights are supposed to come on when you push on the brake releasing the the switch and disengaging it. that means there should already be a constant voltage passing through those wires and pressing the button would cancel that circuit opening another circuit in the engine bay causing them to come on. so that wouldn't work. unless its one of those other type of switches that create a circuit when released which is more likely than what i just said. so if that were the fact then something is grounding out creating the circuit to loop and causing them to stay on. this is so confusing

[moso]

no 2 wire switch gets juice to both leads, it wouldnt work like that. think about it. juice goes to the switch from the fuse, where its inturrupted by the brake pedal being released and pressing the button. when you step on the pedal it releases the button, completeing the circuit and sending the juice to the bulb. the other lead on the bulb goes to ground.

[locoluna825]

that's more than likely how it works but if it worked like that and the pedal was up the switch would stop the circuit, Ive unplugged the switch and the lights STILL stay on so that's the only reason im saying it would work like the other way i explained but it should work the way your saying it does.

[moso]

i know thats how it works, i have the schematic. its in the FSM, you should download it and track down your short. there is even a section in the FSM that tells you how to read schematics. your short is likely unique to your vehicle. if i had to guess where your short was i would guess somewhere behind the dash. the only constant voltage lines in the rear of your car are from the dome and hatch interior lights, all other lines would only be hot when the key was in the ignition. but you have already determined that it is getting power from the brake light circuit by way of fuse removal. so its likely the short is between the only two wires that make up the hot side of your brake lite circuit. these wires only run near each other under the dash between the pedal and the fuse box then the wires split as one terminates and the other goes to the rear of the car.

[locoluna825]

that makes sense i just pulled a bunch of crap off from under the dash it was the old alarms system and was poorly installed,we couldn't start the car because they tapped into so much stuff i finally got everything out and back to stock now it starts. but there was two remaining wires were a purple and gray wire which i thought were part of the sound system. could you link me to that fsm ??

[moso]

hit up the search button and make shure you have adobe acrobat as its likely in .pdf, my friend had an accord that was like that. we ended up replacing the wire harness behind the dash. it wasnt as bad as you would think it to be, altho we did remove the enitire dash.

[locoluna825]

ok thanks ill do the search thing lol