Headlight power hog

Shawn Jackson /

I installed a treats 12v light coil and universal regulator on my puch maxi.

Both yellow and green from coil go into yellow on regulator that is bolted to frame. Red from regulator goes to headlight, tail and brake lights.

Tail and brake lights are 2.5 watt and 1.5 watt ac/dc g4 LED bulbs. I wanted to run a 55w halogen in the headlight but nothing in the tail comes on even if i rev the engine. I reconnected the old 6v 21 watt headlight buld to test and still nothing comes on in the tail.

I thought maybe i had a weak ground at the tail so i ran a wire out side the bike to the place where the head was grounded to check, and that made no difference.

Am i missing something here? Why is the headlight sucking all my power and leaving nothing for the tail lights?

Re: Headlight power hog

Does the tail power with the headlight disconnected?

Re: Headlight power hog

Shawn Jackson /

No lights up nice and bright

Re: Headlight power hog

What you don't realize is that a 6 volt 21 watt bulb draws 3.5A, and a 12v 55w bulb draws 4.5A. That's not a huge difference. Go back over your wiring but take the regulator out of the loop and try it.

Re: Headlight power hog

Dan (LandLordsMG/PSVMC) /

are your LED's installed backwards?

Re: Headlight power hog

Put your meter on DC. One probe on one contact in the lamp socket,the other lead to a good ground. Turn lights on. Any voltage? Set brake,move probe over to brake contact,any voltage?

If nothing you have a blown fuse or a bad/open wire(s).

If you have power, check the new LED bulb and make sure when you set it in place and turn it,you ARE touching the contacts in the lamp socket when the bulb is turned and locked in.

Re: Headlight power hog

This guy... Nothing on that bike is dc powered, absolutely nothing.

Re: Headlight power hog

Shawn Jackson /

Right, all ac on this one...

It looks like there is not enough wattage for both. Headlight is sucking up just about all the amps available. I guess ill have to separate the leads from the coil and send one to the headlight with no regulator and then send the other to tail via the regulator to protect the leds. Hopefully i dont start popping headlight bulbs

Re: Headlight power hog

Check the account voltage at idle. LEDs do have minimum voltage and you likely aren't reaching that at idle. What you can run is called a step up converter that boosts voltage while sacrificing amperage. It would at least get you some light from the cells until the revs climb and proper wattage is output to fully power (if ever) all of the lighting.

Re: Headlight power hog

Shawn Jackson /

I have the voltage at idle. Just no amps to drive it.

I do have the two old tail coils (green and gray leads) is there a way i could link them to get 12v instead of 6? Like stacking batteries i just dont know if that works with ac coils.

If that would work i could put them back in the bike for the tail and use all the juice from the 12v coil for the headlight

Re: Headlight power hog

I meant measure the voltage at idle with the load on it. The point is to tell if the issue is purely low voltage causing the cells not to light.

Technically a coil is not "12v" or "6v". The coil is wound to provide a certain amperage output given a specific voltage. That's why I specified the amp draw of the two bulbs. You can make a 6v stator provide 12v if you lower the amp draw (volts*amps=watts), you will increase the voltage to the limit of the coil. The total number of turns on the coil will limit the potential voltage output. The problem with stacking like coils in parallel is that yes they may potentially provide more output power but they will be limited by the design of the coil itself. Also if the coils are counter wound you will cancel out much of the output (or all if the coils are the same)) and will just be generated as heat between the two coils which could harm them.

If you have two leads from one coil then joining them will not increase anything and may reduce output because one lead is simply a center tap of the full coil. Just use the lead that has the higher resistance.

If you have the space on the stator to run separate coils then you could do it. You won't need a lot to run an LED tail, really nothing special at all.

Re: Headlight power hog

Shawn Jackson /

So with that in mind... if i use the old brake coil that was used to drive a 6v 10 watt bulb meaning it provided 1.67amps

It should be able to drive my leds which are 12v and a combinded 4 watts so the need less than half an amp from the coil.

Re: Headlight power hog

Probably Fred /

Stock wiring With 3 lighting coils work best

I have no idea why people try to make it work worse by adding aftermarket coil then regulator blah blah blah

Stock main light coil is 21w And it can take more (I run headlight, speedo light and cateye turn signals off main coil on all my bikes for years with no failure) watts then 21w

Brake light coil is 10w and tail light coil is 5w so you got plenty for led/other lights and with a regulator you could probably have more output/steady output

The three coil system was designed with no regulator and if you use the correct wattage bulbs the bulbs dont burn out and coils last for decades

It's a very good system but yeah if you're going to hack into it and do other things with it then it was designed to do then you're going to need a regulator at every coil basically.

Re: Headlight power hog

Shawn Jackson /

Trying to get brighter lights. The stock system was not that visible where i live. I could see but cars could not see me. Im trying to keep from getting hit because they didnt know i was there

Ill add the old brake coil and see how my leds in the tail work.

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