No head light

Scorpio1963

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Check the bulb it is working but when on the bike switch on and running no head light.Could my problem be one of those relays near the bottom of the bike?
 
Not eveybody spends all their time just waiting to answer your questions.
But since I'm here I will give you a few things to think about.
You don't mention the year of your bike. A lot os things changed over the years.
Around 78 or 79, maybe 80 they eliminated the headlight on/off switch. They replaced it by adding a second section to the safety relay. When the relay trips to turn off the starter it also turns on the headlight.
The relay trips by bleeding some of the power the alternator creates to trip this relay. If your charging system is not working, then no power to trip the relay.
First thing to check is the battery voltage at idle, about 2000 to 2500 rpms and at around 5000 rpms.
Voltage should be around 12-13 volts at idle, as the revs increase the voltage should rise up to around 14 to 14.5 by around 2000 to 2500 rpms. It should remain at this voltage at any higher rpms.
Leo
 
LEO we go back a couple of years anyone who knows me knows my bike is an 81 xs400.This is not the 1st time my questions have gone unanswered.Ive been a good member,hekpful and contributed my knowledge to help others so theres no reason to be ignored.Last but not least it was a simple question which I searched the forum for to try and find answers but no pertinent info was available hence me asking.
Since you are offering your generous time to help I appreciate it.Today Im going to check something I may have forgotten to do when I buttoned up my bike after being plagued with electrical issues last year.I may have it disconnected inside the bucket.
Now with that said should it be connected inside I`ll check the battery and charging system.The battery is brand spanking new,the bike only has been running again for 2 days.Now I don't know if it usualy works this way but usualy has soon as I turn the key both the head light and tail light are on.I do remember when I went through all my electrical diagnosis last year my flashers stopped working but I also had every unneccesary component of the bike trying to figure out why the bike wasn't turning over.So I`ll check somethings and report back later with what I find out.:)
 
Ok I had sometime to look over my bike,heres the status so far,It runs good but the lectrical still has bugs.My head light is plugged in and doesn't work.the left hand side front turn signal works.The tail light is working with no issues.So what else do I check along with a few questions.Could the reason for my turn signal problem be the flasher relay and what would happen if I removed it?
On the head light since I found out its plugged and the bulb is good what would be the possible cause and what is the next step?
 
Check under the right/left hand switches unit to see if there is rust under it. There are grounding tabs inside the control switches. If it is not properly grounded could be causing the light not to work.
 
Hello where did all of our helpful people go?:shrug:
The weather is great outside.

Sometimes when the answer is simply thorough, hard work, people don't reply.

Could be a broken or frayed wire, bad fuse, or fuse holder connection, corrosion on connectors, corrosion inside switches or relays. Kickstand relay?

My fuses were good but the wiring connection to them was loose and the holders corroded. Had to rebuild the fuse box with new holders and connectors to get rid of electrical ghosts.

If nothing obvious is wrong, test everything.

Disconnect the battery. Get a multimeter/volt tester set to continuity or resistance mode, check the continuity of every individual current path from the battery side of the lights fuse to each thing that's not working, checking each individual wire and connector along the way. Then check from there to ground.
Might have to flick switches, turn keys, or bypass relays to do this.

If everything is connected as per the circuit diagram, and everything conducts properly from fuse, to light, to ground, then it should work.
 
What is so strange about this bike the only thing that would turn was all the lights.the start wouldn't work and even kick starting would get it to fire up.So I went through the entire electrical system replaced all my fuses with an upgrade to blade from the old glass style.No I haven't done the testing as of yet lack of time.I`ll have the bike out tomorrow so I`ll check it along with the fuses.Also what is strange is the two relays down near the bottom of the ride side bottom is the bike has only had one and everything worked like it should:umm:
Norman 1950 I hadeo the light control all aprt tested continuity and everything is good and clean inside of the switch,no rust and control is making a good ground on the handle bars.
 
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Ok I ran the test that xsKeo suggested I have a problem HoustonBAttery fully charged bike off,when bike is running Im losing voltage down to 10.71.Rev up engine voltage stays the same so Im assuming my altnenator is shot or theres a short somewhere.What do I do next?

BB360 checked my fuses and all the connections from what I can tell everything is good.
Hypothetical question can starter soilinoid if bad cause this problem,would the bike run if I somehow crossed the wires?
 
Correction the battery wasn't fully charged it was reading 11.56 volts when I took it off the bike.I have it on a trickle charge and once fully charged will see if it stays there.Leave it to autozone when I bought the battery new they said put at full charge for 2-3 hours which probably fried the battery.:banghead::doh:
 
So guys got a new battery its been charged up the proper way and holding at 13.77 volts.Took the tank off check my relays to make sure they are connected Sill the problem persist.Im not knowledgeable in using a multimeter is resistance mode.I did a continueity test to the head light I have no power,Im lost help please:shrug:
 
Relay kicks the light on when the engine starts/starts to charge.

And as XSLeo said several posts back:

The relay trips by bleeding some of the power the alternator creates to trip this relay. If your charging system is not working, then no power to trip the relay.
First thing to check is the battery voltage at idle, about 2000 to 2500 rpms and at around 5000 rpms.
Voltage should be around 12-13 volts at idle, as the revs increase the voltage should rise up to around 14 to 14.5 by around 2000 to 2500 rpms. It should remain at this voltage at any higher rpms.
Leo



So until you get the thing to charge you are wasting time worrying about the head light.

You said the voltage did not go up with it running so I'm pretty sure it is not charging and if no power is going to the relay to turn one the headlight you are not going to see it come on.
 
Will do I had to put the bike away temporarily because of bad weather and no indoor place to work on it.I was in the middle of doing voltage and continuity testing when it started raining buckets.:yikes:

Quote I've read on the forum that if one bulb is blown than the others won't work either. Or if the indicator bulb is blown the flashers may not work? Perhaps I should start by taking the indicator panel off and checking that? Quote

I may also have some burn out bulbs and will be checking them.
 
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Quote I've read on the forum that if one bulb is blown than the others won't work either. Or if the indicator bulb is blown the flashers may not work? Perhaps I should start by taking the indicator panel off and checking that?

I'd stick with finding out why you are not showing a charge with engine running, OUT PUT FROM ALTERNATOR IS WHAT TURNS ON THE HEADLIGHT RELAY.
 
hERES THE DEAL WITH THE HEAD LIGHT,WHEN I COULDNT GET MY BIKE TO EVEN TURN OVER OR FIRE UP ALL THE LIGHTS WERE WORKING IT WASN`T TILL I STARTED TAKING OFF AND CHECKING RELAYS WHEN THEY STOPPED.iTS PROBALY SOMETHING SIMPLE THAT iM OVER LOOKING BUT I`LL LOOK INTO THE CHARGING SYSTEM ALSO.i ALSO CHANGED KICKSTAND RELAY AND I HAVE EXTRAS SO CHANGING THEM MAY BE THE A SALUTION TO THE PROBLEMATIC LIGHT.THANKS FOR CHIMING IN TO HELP AARON
 
Dirty relay connection. Had it happen to me in the past. Very easy fix.
 
I did another voltage test like XSLeo suggest.My voltage is increasing as I rev up the rpms.
I also did a comueity test on the plug to the head light,theres power of sort when I test for ohms or resistance.The number on my meter was 23-26.I don't realy understand what that means?:shrug:
XSchris I`ll check those relay connections like you suggested and hope that's all it is.I know they were working last year before I took everything apart.
 
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