Headlight issue

Boles44 said:
i have an 81 xs650 and yesterday my headlight worked but now it is no longer working. I looked through the glass and the bulb doesn't look broken(not too sure). Do you have any tips on diagnosing this issue?
Click to expand...

Hi Boles,
what's supposed to happen is that the headlight automatically turns on when the safety relay sees Voltage from the alternator after the engine starts and stays on even after the engine stalls until you turn the key off.
Neither filament lights up? It's unlikely that they both blew at once.
Check the headlight fuse.
Check that the alternator is working.
Check the power through the dip-switch.
Check every last little wiring connection.
And yeah, check the bulb anyway.
 
Hi Boles,
the quick & dirty alternator test is to point your headlight at a wall and rev the engine.
If the light gets brighter the alternator is working.
No good in your case as the headlight isn't working.
Mebbe the tail light?
A better test is to put a multimeter on the battery terminals as you rev the engine.
Battery at rest should read 12V/12.5V. At 3,000rpm the battery should read ~14V.
All the fuses are in a little plastic thingy atop the battery.
 
tail light works fine and i checked the reading on the battery and it was charging. it might be a ground but im going to test the bulb tonight
 
Hi Boles,
I meant, see if the tail light brightens when the engine is revved.
I've only ever watched for the headlight to get brighter, dunno if the tail light's brightening would be enough to see.
The most likely culprit is a failed solder connection in the dip-switch.
 
Dip-switch. Headlight dimmer switch. The unit on the left-side handlebar next to the clutch lever which contains the switch to work the signals, the switch to select between high and low headlight beams and has the horn button too.
Kinda complicated in there and frail besides. Designed to last for 5 years max and that was 30 years ago.
 
Very useful old thread here.
I jumped my wires and have a high beam when I switch the bike on, but no low beam. I've got zero relays on the bike so I doubt I'd need to have the bike run
 
Hightower-Ash98 said:
Very useful old thread here.
I jumped my wires and have a high beam when I switch the bike on, but no low beam. I've got zero relays on the bike so I doubt I'd need to have the bike run
Click to expand...

Hi -Ash,
perhaps you jumped the wrong wire? Either headlight filament should work if you jumped the wire that sent power to the dip-switch.
 
you can test the bulb with a meter -- just look for not open from the terminal that gets the black wire to the other two.

it's not uncommon for the handlebar switch to be bad -- just measure and see where the ~12v stops and you'll be where the problem is. they can develop bad solder joints, just resolder all the joints
 
xjwmx said:
you can test the bulb with a meter -- just look for not open from the terminal that gets the black wire to the other two.

it's not uncommon for the handlebar switch to be bad -- just measure and see where the ~12v stops and you'll be where the problem is. they can develop bad solder joints, just resolder all the joints
Click to expand...
Brand new switch. I tested the bulb itself with a 12v battery, it lit up in both positions.
I doubt I jumped the wrong ones because the light wouldn't work at all I'd assume.
Maybe I have the plug for the light crimped incorrectly.
 
in that case, switch is prob wired wrong, or maybe wrong switch. if you can open the switch up, just trace the circuit with your eyes.

you can also use the meter on the switch -- see if there's the path you expect with the switch in various positions
 
xjwmx said:
in that case, switch is prob wired wrong, or maybe wrong switch. if you can open the switch up, just trace the circuit with your eyes.

you can also use the meter on the switch -- see if there's the path you expect with the switch in various positions
Click to expand...
I did in fact, have the incorrect wire ran to the headlight. Now I've got high and low beams. Anyone know what may be causing my turn signals to not work?
 
Hightower-Ash98 said:
I did in fact, have the incorrect wire ran to the headlight. Now I've got high and low beams. Anyone know what may be causing my turn signals to not work?
Click to expand...

Hi -Ash,
not work at all, all 4 on, steady or fast flash?
Wrongly wired​
On steady when switched but no flash? Low wattage bulbs + stock flasher.
 
^There's no relay in the flasher circuit. Do you have a circuit diagram? Even if you're doing custom wiring, it can help immensely
 
Hightower-Ash98 said:
No power at all. Is there a relay I need to purchase or what? I don't get any power to any of the wires
Click to expand...

Hi -Ash,
well, no, you hafta put it there. Does your wiring attempt include an ignition switch?
If so, run a "hot" wire from the switch terminal that is powered when the key is turned to ON to the flasher switch.
 
fredintoon said:
Hi -Ash,
well, no, you hafta put it there. Does your wiring attempt include an ignition switch?
If so, run a "hot" wire from the switch terminal that is powered when the key is turned to ON to the flasher switch.
Click to expand...
I bought a factory style harness pre made. I get power to headlights after splicing the wires mentioned in this thread. With the ignition on, I get horn, light, the bike runs and drives. I do not get any power to turn signal wires. As also mentioned I have none of the extra factory gear, reserve lighting unit, which I understand doesnt matter. I've got no flasher relay, I've got no headlight safety relay, or any of the other electronics.
 

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