A forum for owners of Yamaha TTR250 trail and enduro bikes!

nwrider · Veteran Member

rear light

TTRfan · Super Guru

I have the same problem and will be interested to see if anyone has a possible solution.

TDVT · Senior Member

Don't know if I'm understanding this right, but you're burning out the tail light filament half of the rear bulb, but not the brake light section?

TTRfan · Super Guru

TDVT wrote:
Don't know if I'm understanding this right, but you're burning out the tail light filament half of the rear bulb, but not the brake light section?

Yep cry

Cubber · Super Guru

Does that not indicate a poor earth? confuse

Worth checking for nowt. wink

Martyn

nwrider · Veteran Member

bad planet? how do i check the ground?

Cubber · Super Guru

I'd run a new, separate earthing wire from the bulb holder to convenient earth point on the frame rather than rely on the OE wire which may be corroded. smile

Martyn

TDVT · Senior Member

Checking the ground is a place to start as a bad grouns can cause all sorts of weird problems.

But I went back & read your posts in another thread when you were getting the bike street legal & I'm not sure you have it wired correctly. That could possibly explain the bulbs burning out & also the LED not working, as LED's use less current than a regular bulb.

On our US-spec bikes, the brake light is there, has the right dual-filament bulb & the socket is wired for a brake light but the brake light half is not connected to anything. The wire bundle from the tail light has 3 bullet connectors tucked down next to the frame right near the airbox snorkel. The yellow one is unused.

As you already know, the three wires are:

black- ground

blue- tail light

yellow- brake light.

The blue is fed from the "lights on/off" switch on the bars. If you tap the blue wire to feed your brake light, then the brake light will only work if your other lights are on.

To add a brake light that is independent of the other lights (like a car or truck) you need to run a new 12v+ feed to one side of your new hydraulic brake switch (both wires on mine were yellow, use either one). For a feed, I tapped one of the brown wires under the tank when I did mine. These power the lights, CDI, etc. but are switched off with the key.

Then from the other side of your hydraulic switch, run a new wire to vicinity of the air box snorkel & connect that to the yellow wire that runs to the brake light half of the rear bulb.

That should do it. If you have a hydraulic switch on both front & rear then you need to wire the switches in parallel but otherwise the wiring is the same.

Hope that helps.

nwrider · Veteran Member

my light works, as a running light, when light switch is on and then i ran a hydraulic switch into the yellow and has been working great. Should the leds be a plug and play? i had to grind down the light housing to make it fit, but only the running lights work, what would cause the brake lights not to work? should i run a bigger fuse? cubber-- just anywhere on the frame?

Cubber · Super Guru

The BEST location to make an earth connection for anything electrical is to the battery lead used as earth. smile

Obviously, if the battery is earthed to the frame then any metal to metal contact of the frame will be good.

It's best to scrape the paint off the frame and bare the insulation off the wire to make an earth connection. It would then benefit from a coat of paint or Vaseline or grease to protect it. wink

Don't make the earth connection to anywhere on the mudguards or side pods - these are plastic! disbelief

Martyn

barra8 · Guru

Sounds to me someone has their wires crossed (Sorry could'nt resist lol :)

Firstly check wires are in the right place eg.

Yellow to yellow ''power wire'' (goes to brake light assembly wiring for brake light) ONLY ONE WIRE FOR YELLOW NOT TWO PLUGGED INTO YELLOW!!!!WITHOUT IT YOUR BRAKE LIGHT WON'T WORK!!! 

two connections ''DOUBLE BULLET CONNECTION ''SAME PLUG ''black = ground (earth) ONE for tail light/ ONE FOR number plate light

two connections ''DOUBLE BULLET CONNECTION ''SAME PLUG'' blue =''power wire'' ONE FOR tail light ONE FOR number plate light

Note: black and brown (longest wires ''end of wiring harness'') are indicator wires

Next check the power wires are not earthing (grounding) on the frame or crossing each other anywhere.

Then check your battery leads + the bolt that holds the starter relay on (above brake switch).Is it loose/earthing to frame/grounded properly???

Adjust brake light switch if not returning properly and staying on acting like tailight (maybe your problem from the start) eg. you may be using the stuck on brake light for a tailight with no yellow as mentioned above for the brake light.

Last is the main ground (earth) located on the frame where the bolt bolts the regulator, is it loose?burnt?dirty??

REMEMBER: ALL WIRE== COLOURS SHOULD MATCH THE WIRE ==COLOUR IT IS CONNECTED TO!!!! BLACK and Green are commonly used as ground wires (earth).

NOTE: You should only run the specified amperage and voltage eg. tail light

: 12 V 5W/21W (or only slightly higher)with all bulbs except headlight: 12V /35W 36.5 or blown bulbs/burnt wiring/stator (ac magneto) will be the result

Warning: There is a reason i mentioned it in the correct order because if you just use a separate earth from the start without checking all mentioned first you could just burn whats left of your wiring and stator/coil/cdi/EXPENSIVE!!! out when it has a good earth. ie: Wires crossed=burnt wires when a good earth is gained, Power wires earthing on frame=burnt wires/stator ect.

Also if your main earth wire burns out there is usually a problem eg. Crossed wires/power wire earthing/battery power lead earthing to frame ect...

If all else fails check your fuse is the correct amperage (located above the starter relay ''kickstart side'' usually unless moved) .

Other than that it's time to buy a new wiring harness. I suggest this AU $ 101.00 from this site

http://www.partforyamaha.com/pages/OemParts?aribrand=YAM#/Yamaha/TTR250_-_TTR250MC_-_2000/ELECTRICAL_1/TTR250MC_(2000_MOTORCYCLE)/ELECTRICAL_1_(TTR250MC_-_2000)

Good luck.

-- Edited by barra8 on Friday 10th of August 2012 02:58:00 PM

blackmaverick · Newbie

Messure the voltage at the following points:

- Across the bulb connections.

- Positive side of the bulb to the negative side of the battery

- Positive side of the bulb to a good earth point on the engine.

This will give some diagnostic information.

barra8 · Guru

Haggis Hunter wrote:
I agree with Blackmaverick. Check the voltage at the bulb holder between the pins and between the positive side and the battery negative. A much better reading on the second test would indicate a poor earth.
Had a van that was getting through bulbs, checked the voltage and found it was running over 16V at times. Regulator in the alternator was replaced and it never blew another bulb.
My old raid has been run every day for 7 years, the tail light is on all the time and it has never had a bulb replaced.

Peter

Anyone with a multimeter and sound understanding with wiring would be better off using this method although this info is in all manuals so aint too hard to get hold of that info. The info i have given above is not in the manual and you don't need much understanding with wiring to know what i'm saying.

Somehow i think getting the wires right and making sure ''power'' wires are not earthing on frame or crossing over,correct bulb etc. (as mentioned in my first post)would be the main thing though not just whether it has a good earth.

Read this because nobody seems to have even read my post before passing judgement

Warning: There is a reason i mentioned it in the correct order because if you just use a separate earth from the start without checking all mentioned first you could just burn whats left of your wiring and stator/coil/cdi/EXPENSIVE!!! out when it has a good earth. ie: Wires crossed=burnt wires when a good earth is gained, Power wires earthing on frame=burnt wires/stator ect.

Also if your main earth wire burns out there is usually a problem eg. Crossed wires/power wire earthing/battery power lead earthing to frame ect...

-- Edited by barra8 on Thursday 9th of August 2012 12:56:38 AM

barra8 · Guru

brindabella wrote:
just to go back to basics for a while..

we have a taillight bulb, made by manufacturer "x".

it, anyway, is a miracle of technology that taillight bulbs work for more than 10 minutes.
as they have a tiny wire, vibrating constantly and maybe fed by a varying voltage,
and going through hot-cold cycles at very high temperatures.

1. maybe manufacturer "x" makes bad bulbs?

2. if there is more than 12V (eg at high revs), it is more likely to burn out - this could be the regulator,
or earthing or connection problems related to the regulator and battery circuits
but is hardly likely to be related to a earthing problems in the taillight wiring.
it could also be that the headlight is not working, causing a reduced load and slightly higher voltage.

3. if there is vibration (loose taillight assembly, fender etc) the bulb obviously won't last as long;

4. if there is a loose electrical connection, the intermittent on/off might put the bulb through lots more
heating and cooling cycles, and obviously it won't last as long.

If you were to observe the bike in operation from behind and noticed flickering (with road bumps etc)
or variations in intensity with speed, you would have a valuable clue.

Good info but as nwrider mentioned he has been using the yellow wire (brake wire)for a tailight wire. Eg...
my light works, as a running light, when light switch is on and then i ran a hydraulic switch into the yellow and has been working great. .Obvious problem...

He didn't mention problems with battery or headlight so that's why i don't think it has anything to do with the regulator/resistor...

Jarrah.

This diagram should make it clear as to how the wires should be....

-- Edited by barra8 on Thursday 9th of August 2012 02:48:25 AM

Haggis Hunter · Veteran Member

I agree with Blackmaverick. Check the voltage at the bulb holder between the pins and between the positive side and the battery negative. A much better reading on the second test would indicate a poor earth.

Had a van that was getting through bulbs, checked the voltage and found it was running over 16V at times. Regulator in the alternator was replaced and it never blew another bulb.

My old raid has been run every day for 7 years, the tail light is on all the time and it has never had a bulb replaced.

Peter

barra8 · Guru

Thought i would make it easy for you as my original post may be hard to understand...

First check that the brake light switch is turning off the power to the yellow wire located at the rear end under seat.

Note: it is easy to find the yellow wire its the only yellow wire that is under the seat that is about 10cms from the back (rear)of the airbox

You can do this by using a test light (any 12v light) or multimeter and testing the yellow wire

Does it have no power when brake lever is not pushed in?

If it does have power adjust it until you have no power when the brake lever is not pushed in

Then check you have power in the yellow wire when the brake is applied

If you do not have power in the yellow wire at the exact moment the brake is applied a faulty brake lever switch or crossed/burnt wires is a problem to be fixed.

Next...

Check the blue double bullet connection located same spot as yellow wire mentioned (under seat)and make sure one blue connection goes to the blue wire tailight wire and one blue connection goes to the blue wire ie.number plate light. NOTE; ''POWER WIRES'' these should have power when ignition is on and the Headlight On Off Handlebar Control Switch is on (if fitted)

Next..

Check that the black double bullet connection located same spot as yellow wire mentioned (under seat) and make sure one black wire goes to the the black wire on the taillight and one goes to the black wire on the number plate light. Note: EARTH WIRES

Note: The tailight and brake light have the same earthing ''grounding'' point ''wire'' as each other

Note: All wires should match the colour it is connected to eg. blue==blue...yellow==yellow...black==black

First check this and all mentioned in my first post (too long to repeat)then refer to the repair manual to check resistance and voltage/amperage of wires to see if any are out of spec..

I uploaded a pic of the tailight/brake wires,hope you can tell the different colours in it....

Good luck

-- Edited by barra8 on Thursday 9th of August 2012 07:24:41 PM

brindabella · Senior Member

just to go back to basics for a while..

we have a taillight bulb, made by manufacturer "x".

it, anyway, is a miracle of technology that taillight bulbs work for more than 10 minutes.
as they have a tiny wire, vibrating constantly and maybe fed by a varying voltage,
and going through hot-cold cycles at very high temperatures.

1. maybe manufacturer "x" makes bad bulbs?

2. if there is more than 12V (eg at high revs), it is more likely to burn out - this could be the regulator,
or earthing or connection problems related to the regulator and battery circuits
but is hardly likely to be related to a earthing problems in the taillight wiring.
it could also be that the headlight is not working, causing a reduced load and slightly higher voltage.

3. if there is vibration (loose taillight assembly, fender etc) the bulb obviously won't last as long;

4. if there is a loose electrical connection, the intermittent on/off might put the bulb through lots more
heating and cooling cycles, and obviously it won't last as long.

If you were to observe the bike in operation from behind and noticed flickering (with road bumps etc)
or variations in intensity with speed, you would have a valuable clue.

nwrider · Veteran Member

how do i a get a bigger pic, of wire diagram. No prob with head lights or starting the bike at all

barra8 · Guru

nwrider wrote:
how do i a get a bigger pic, of wire diagram. No prob with head lights or starting the bike at all

If you pm me your email address as it is too large too fit here i would be happy to send you a pdf. full workshop manual with a large diagram included...

Regards,

Jarrah.

nwrider · Veteran Member

I am sorry its been a while, today I finally asked my neighbor who was a bike mechanic. He brought over a tester, and found a small crease in a wire and would sometimes hit something under the seat. replaced and hopefully it fixes it.