Yamaha dt 125 regulator or battery problem.

[Guest]

Hey guys i am having trouble starting my 06 yamaha dt 125.

its been cold and snowy and i hadn't started my bike for a good couple days, when i came to start it i turned my ignition on and i got no ignition lights and none for the lights or electric start were working.

I bought a new battery and put it in today with no luck i have the same problem still, the alternator is working fine because i have to bump start the bike to get to work.

Do you think i need a new regulator rectifier and could that be screwing up my new battery?

Cheers for any feedback.

Jimmy

[eastanglianbiker]

if you are getting no lights up on dash with ign turned on its not reg/rect problem you need to check voltage of battery with ign turned off then turned on it should drop slightly if live feed is passing through ign then start bike up check voltage on tickover and again at about 3500rpm on tickover should be about 12v and at 3500rpm should be about 14 volts.also spray ign up with wd40 down in where the key fits and all round the rear of the ign if u can get to it

[Guest]

so if the voltage is too low it wont be able to start the bike or turn the lights on.

and if the voltage is too low does that mean just charging it up and then it should ignite or is there other reasons this could be happening?

[Tango]

Some new batteries need charging before you use them......so it may be just a case of charging the battery......

[Guest]

do sealed batterys need 8hrs or 12 hours charging, and i got told when buying it that i wouldnt need to, but ill try it.

[Tango]

Charging time depends on how much charge is left in the battery......which sounds like not a lot from what you've said....... Batteries will discharge even without anything connected to them.....so if your new battery has been sat on a shelf somewhere for a few months it could well have lost its charge.....

[Guest]

ahh ok, so if i give a blast overnight it might work? and will a voltage check give me an idea of how much juice its got?

[Tango]

A voltage check can give an indication how much charge is in the battery.....but remember that it will possibly show 12v off load......so check it when on the bike and then switch the ignition on and see if the voltage drops.....which would indicate low charge......

[Guest]

ok so check the voltage when ignition is set to on and then turn it of and check or check when the bikwe is actually running and then switch the ignition off and check?

Also if iv been riding the bike with the battery in wouldnt that give me enough charge to show ignition lights?

[Tango]

First check the battery voltage with the ignition off.......should be 12.5v approx......then turn the ignition on (I'm guessing that the lights should come on also) and the voltage should drop slightly....but no less than 12v. Then start the bike and measure the voltage......should be >13v especially if you rev the bike to around 3000rpm.

The main thing is that if the battery is good and charged it shouldn't drop below 12v when you switch the ignition on....well, not immediately anyway. Obviously with no charge going into the battery without the motor running the voltage will drop gradually...but it shouldn't collapse as soon as you put a load on it.....

[Guest]

ahh ok but when i turn the ignition on i get no lights atall.

and thanks for your help this is teaching me loads!

[Chrissb6]

Hi, you said that you have a fully charge battery and yet no lights at all, have you checked the main fuse? You should never run the motor without the battery connected or with a battery in a state of deep discharge as this will trash the voltage regulator. Try and get a wiring diagram check the battery connection and earth strap and work your out from there. I suspect a blown fuse as you at should at least have dash warning light and brake lights, even with no engine running. Best of luck.

[Tango]

ahh ok but when i turn the ignition on i get no lights atall.

and thanks for your help this is teaching me loads!

 

That's the point really......if you have 12v on the battery with the ignition off but it drops to a couple of volts or less when you turn the ignition on it suggests that the battery is either not charged or is faulty. When you say you can start the bike by bumping it do the lights come on then? If so, there's no fuse problem.....just a discharged or duff battery.....

Try charging the battery overnight and see what happens tomorrow.....

[Fozzie]

Take voltage readings when the bike is off, running, and with the ignition on but not running.

If you have a rec/reg failure you will just drain the battery but it may have only broken down. Some bikes seem to keep going with a bump even with the rec/reg gone.

But first things first, just measure the volts

However did the new battery make no difference at all?

Most batteries these days dont require a charge when taken out of the packet so if it says dont, then dont. Manufacturer knows best. Even when low voltage the lights should still light even if dimly.

So if the lights arent on at all or come on when the engine is finally started then it sounds like a electrical problem, likely a wiring or relay issue.

[Guest]

Hi there,

I have just put my DT 125 X supermoto model back together,

I had everything running fine, then i had the same problem, all electrics cut out none of it works,

I can bump start it fine and runs fine, but just no electrics, no lights no horn no starter motor, im thinking this could be the same problem, so was there a solution to this problem ever resolved ??

thanks P

[snelle_erry]

hi guys,

I also have this problem. I can only bumpstart my dt125 but no lights etc. I'm thinking its a relay/regelator problem. becase the battery is good and the fuses nex to the battery are good also.

how did you guys fixed the problem?

[dynax]

hi guys,

I also have this problem. I can only bumpstart my dt125 but no lights etc. I'm thinking its a relay/regelator problem. becase the battery is good and the fuses nex to the battery are good also.

how did you guys fixed the problem?

 

it's been 6 years since the last post so i suspect they called in a priest to deliver it's last rites

[bud]

Check the fuses for with a multimeter. Sometimes they look ok, but are defective

[husoi]

Check the fuses for with a multimeter. Sometimes they look ok, but are defective

 

Or the contacts to the fuse box

[WD-40]

hi guys,

I also have this problem. I can only bumpstart my dt125 but no lights etc. I'm thinking its a relay/regelator problem. becase the battery is good and the fuses nex to the battery are good also.

how did you guys fixed the problem?

 

What year and exact model is it?

[Mississippi Bullfrog]

If you have no lights then either there's an electrical break somewhere or your battery is discharged. A discharged battery may still show good voltage when checked off load.

Give it a trickle charge then try it.