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View Full Version : Brake lights wont turn on w/ headlight but work with pedal (braking).


Siberian Husky
08-22-2010, 05:12 PM
As the long title says. My brake lights wont turn on when i turn the headlights on, but they light up when I brake. Also, turn signals wont turn on and gauge cluster wont light up with headlights. Where should I start trouble shooting?

I stripped the interior and unplugged most things to take dash out, but I have the cluster plugged back in, and I'm not sure why the brake lights are acting funny or why im not getting signal lights to turn on.

DMACHINE188
08-22-2010, 05:47 PM
Blown fuse

Siberian Husky
08-22-2010, 06:57 PM
is there a diagram where i can see what fuses belong to what? cant seem to find one.

SilviaAura
08-22-2010, 07:23 PM
look on driver side foot well... open the fuse box looks like this http://a.imageshack.us/img157/2397/carjuly1zc7.jpg
check the 15a fuse under tail lamp. its the third one up on the right...check that first...ill stay on this to try to help you out...

Pacman
08-22-2010, 09:50 PM
The taillamp fuse circuit is tied into the dash wiring, at least my S14 is that way. If the dash lights still work then you have problems elsewhere.

SilviaAura
08-22-2010, 10:09 PM
but his dash and tailights went out...that points to a bad fuse or bad connectors but somewhere around the fuse box area is my guess

joeapple8
08-23-2010, 01:12 AM
TCU - timing control unit, check that if your fuses are not blown...

I have a bunch of these for sale

Taylor008
08-23-2010, 04:58 AM
TCU. Also check your headlight switch in the steering column.

Pacman
08-23-2010, 10:00 PM
but his dash and tailights went out...that points to a bad fuse or bad connectors but somewhere around the fuse box area is my guess

After re-reading that, him saying his brake lights won't turn on until he hits the brakes or whatever threw me off.

If the TAILLIGHTS don't work and dash lights don't work, then yes, a fuse sounds blown to me. If not the TCU. :)

Siberian Husky
08-26-2010, 01:51 PM
headlights turn on on steering column.

brake lights turn on when braking.

my problem is that there is no turn signal, front or back, no turn signal on cluster, and no brake lights when headlights are on. but brake lights come up during braking.


hope that clears this up.

EDIT: there is also no door chime when key in ignition and the seatbelts do not auto correct (s13) when door opens unless engine is ON.

is this also TCU evidence?

drift freaq
08-26-2010, 02:04 PM
headlights turn on on steering column.

brake lights turn on when braking.

my problem is that there is no turn signal, front or back, no turn signal on cluster, and no brake lights when headlights are on. but brake lights come up during braking.


hope that clears this up.

EDIT: there is also no door chime when key in ignition and the seatbelts do not auto correct (s13) when door opens unless engine is ON.

is this also TCU evidence?

Check your turn signal column switch stalk. They can and do short out causing all kinds of electrical Gremlins in the gauge cluster, brake lights and turn signals.
Had the same issue no brake lights when headlights were on and then the gauge cluster blacked out. Changed out the stalk, problem fixed.

Basically any kind of short in that whole system will cause a chain reaction failure. Usually its the column stalk switch that is the culprit.

roboticnissan
08-26-2010, 02:33 PM
Check your fuse. You always start with the easiest and cheapest fixes first. Can't believe you started taking out the dash before you checked a fuse. Common sense meng, use it,don't have any? GET SOME!!!

Siberian Husky
08-26-2010, 02:35 PM
no i became aware of the problem AFTER i took the dash and stripped the interior. i was prepping to repaint the interior and maybe lay some new carpet down as well as swap dash and spray bomb the rusted dash frame...got it running again and thats when i became aware of the issue. i'll check fuses as soon as i get home.

and i do have common sense =(

:lfault:

sorry, just wanted to use that.

DreamN
08-26-2010, 03:00 PM
have you done any of the things mentioned yet? this problem of yours should have been fixed right off the bat.

replace all your fuses in your driver side kick panel with the light up ones. they're cheap and make guess work easier.

If that doesn't work replace the TCU with a known working unit. They're cheap. Shouldn't be more than $10 or so.

Still not working? Replace headlight stalk.

If this doesn't fix your issue then you have a wiring issue. Possibly tugged around and loosened something when stripping your interior. Check connectors.

Siberian Husky
08-26-2010, 08:57 PM
blown 15a t lamp fuse, replaced. but i still get no turn signal. is that 10a turn signal the one for my signals?

RebornS14.HTC
08-26-2010, 09:05 PM
what your missing is the "parking light" which uses the same bulb as the brake light (double filament bulb) check the turn signal fuse and hazard.

Siberian Husky
08-26-2010, 09:27 PM
sorry i forgot to mention. after replacing the 15a brake light fuse, my brake lights turn on with my headlights. so that is solved. what i need now is for my turn signals to both turn on and show up on my gauge cluster when activated, but the 10a turn signal fuse is good, i even replaced it.

dreamin240sx
08-26-2010, 09:28 PM
id check some of the relays also

Siberian Husky
08-26-2010, 09:58 PM
the relays are those larger apparatuses that are located in a box near the battery under the hood, correct?

mxexux
08-26-2010, 10:20 PM
Reading all the post so far I am pretty confident in saying that while you were taking out your dash you might have unbolted a common ground. Ground issues always show up in the manner that you are describing. Since ground is not available directly to the chassis current will flow into the other components that it shares the ground wire with. This will also cause the circuit to overload and blow fuses. Look in the FSM and figure out where all these components ground at and check it.

Hope this helps.

Siberian Husky
09-03-2010, 01:43 AM
Where can I get a hold of the FSM online? I heard it is available for free.

EDIT: http://forums.nicoclub.com/240sx-fsm-full-service-manuals-s13-s14-ka24e-ka24de-t311075.html

projectRDM
09-03-2010, 09:32 AM
The flasher unit controls the turn signals, as well as the hazard switch. Either of those unplugged will not allow the signals to work. Since you took the dash off you likely unplugged one or both. Plug them back in.

And quit saying brake lights in reference to the parking lights. They're two different things. Your parking (or tail) lights come on with the headlight switch. Your brake lights only come on when you depress the brake pedal.

Siberian Husky
09-03-2010, 01:00 PM
The flasher unit controls the turn signals, as well as the hazard switch. Either of those unplugged will not allow the signals to work. Since you took the dash off you likely unplugged one or both. Plug them back in.

And quit saying brake lights in reference to the parking lights. They're two different things. Your parking (or tail) lights come on with the headlight switch. Your brake lights only come on when you depress the brake pedal.


thank you, didnt know the nomenclature differentiation.

Siberian Husky
09-04-2010, 08:21 PM
So i pugged my hazard switch back in. Hazards work, but signals still dont work.