Headlight Circuit??????

mo650chopper · Posted: August 12, 2005, 8:38 pm Post subject: Headlight Circuit??????

Does anybody have a wiring diagram for a 1980 XS650 that shows what the switch / Control does instead of just showing the different wires that go to it? I'm getting frustrated trying to figure out how the "Safety Relay " and "Lighting Reserve Unit" actually work. I can figure out wiring schematics on Chillers, Boilers, High Rise Office Building Controls, UPS's, ATS, Generators but not Japanese Motorcycles, ARGH!!!!

650rider · WebMaster Joined: Feb 09, 2005 Posts: 431

I hear that. Here is a link with Wiring Schematics on it, you may have it already but it's all I can come up with at the moment. I'm did a major google search and came up with nada. But I have to ask; you do use a test/volt metter correct. Don't get crazy I had to ask . . .

http://www.650motorcycles.com/schematics.html

mo650chopper · Posted: August 13, 2005, 7:35 am Post subject: Re: Headlight Circuit??????

Yes I know how to use a meter. I'm not use to looking at wiring
schematics that don't show the interior workings of the switch, coil, capacitor,
diode, Etc. I found quite a few here:

www.650motorcycles.com...atics.html

And one I think may help explain the workings of the Safety relay and
reserve lighting unit here:

www.650motorcycles.com...3-3bob.jpg

I'm assumeing that the saftey relay is what controls the headlight to come on
after the engine fires. So I want to know what else it controls as well as
what wire it uses for control and what wires it turns off / on. Also excactly
what is the purpose of the reserve lighting unit and what does it do? Is it a capacitor? Switch?
Both? Does it also turn on the high beam circuit in the event of low beam failure
or Vice Versa.

mo650chopper · Posted: August 13, 2005, 11:04 am Post subject: Re: Headlight Circuit??????

This all originated with my headlight replacement from this topic:

www.650rider.com/Forum.../t=75.html

I put a toggle switch in the low beam wire to the headlight. It is a three position
switch so I could run with no headlight, the 5 Watt daytime light or turn on the lowbeam.
I purposely left the high beam circuit alone in case of a failure with my wiring.
What would happen with the toggle in either off or switched to the 5 watt daytime
light something was powering up my low or High beam with a reduced voltage.
Kind of defeating not running my normal low beam all the time. I figured it had
to be the lighting reserve unit or Safety Relay. I finally got it to work correctly by removing the
Reserve Lighting Unit and jumping the L/B wire to the L/G wire that feed the lighting reserve unit.

Now it works the way I envisioned and hopefully will be more reliable with one less older part to fail.

Jacksonb289 · Posted: October 14, 2005, 7:48 am Post subject: Re: Headlight Circuit??????

i know this thread is a little old but hoping somone will pop in and read this anyway. I have a 1980 xs650 that is giving me fits with the headlight. A week ago i fired up the bike and no headlight or instrument lights. also no illumination of the "headlight" idiot light between the guages. But the tailight works rock solid from the moment the ignition key is turned. I just shut it off and used the car to go to work that morning.

That eve i fired up the bike, same thing. Until i reved the motor to about 3k. as the revs fell the lights came on and worked properly, i couldnt shake, rattle, or do anything that adversly affected the lights. But everytime i shut ignition switch off and tried again, i had to do the same thing, rev the engine to get the lights working.

Well i didnt have time to dig into it so the bike sat for about 4 days. Now i fire it up and nothing, no matter what i do i cant get the headlight or instrument lights to come on. who knows this may change again by the time i get home tonight.

But i did notice that after sitting for 4 days(by far the longest idle time of the summer) i had very little battery power and had to put a charger on it just to get it started. The battery was new in june, about 4,000 miles on it. I'm not sure where to start looking for the problem, the ignition switch maybe or is there something in common with the charging problem?

Btw, this bike has only 8500 miles on it. but it did sit for years and years at around 4,000 until i got ahold of it in june. It was always garaged and other than this has been completly trouble free all summer. There is no noticeable corrosion anywhere on the bike, the wiring and all connections look new.

Any ideas or guidance would be appreciated.

Tomterrific · Posted: October 14, 2005, 11:12 am Post subject: Re: Headlight Circuit??????

copied from yet another forum.

a member from another forum who is much more knowledgeable than me, gave me these instructions to bypass your reserve lighting unit. Your dimmer has a black and yellow lead, clip and cap it, it also has a green and blue lead, do the same to it. It also has a blue and yellow lead. There is also a blue and yellow lead off of the ignition switch. You should be able to tap the dimmer switch blue and yellow lead into that, using a 1-2 connector and capping off the loose end of the dimmer switch wire. You can also stick a switch in on the dimmer lead side of the split. Hope that helps you out, if it does, you can thank one of the old timers from another forum who knows motorcycles and knows how to wrench em.

Tomterrific · Posted: October 14, 2005, 11:18 am Post subject: Re: Headlight Circuit??????

Try this also. This is what I was looking for.

www.excess650.co.uk/ti...tricks.htm

Tom Graham

mo650chopper · Posted: October 14, 2005, 5:13 pm Post subject: Re: Headlight Circuit??????

Jacksonb289

I think what is the cause of your issue is with the "Safety Relay" as opposed to the "Reserve Lighting Unit" The "Safety Relay" keeps the headlight circuit off untill the engine starts and then the altenator power closes the relay bringing your headlight on. My guess would be something wrong in a charging system componet or a bad connection rather than the "Safety Relay" itself. I have not had to figure how to wire around one yet as mine is still working, So far anyway;)

grizld1 · Posted: October 14, 2005, 7:35 pm Post subject: Re: Headlight Circuit??????

Glad ya like that rig, Tom. It was passed to Yamaha 650 Roadhouse via a personal message on the Proboards18 site a while back.

Wilkinotti · New Member Joined: Oct 23, 2005 Posts: 4

Hello-
New member here, I recently ran into a similar problem with my 1980 XS650. My headlights and gauges stopped working after I replaced the battery. Electric starter, tail light, brake lights, and neutral indicator all work, and all my fuses are fine.
I've tried a couple of replacement Reserve Lighting Devices; that hasn't solved the problem. My guess is it's either the Safety Relay or the alternator itself--can anyone offer any wisdom as to which is the better place to start?
Thanks!
Rob W.

mo650chopper · Posted: October 23, 2005, 8:33 pm Post subject: Re: Headlight Circuit??????

If you have a volt meter, If not I would suggest you get one, Check and see if your charging system is operating. You should get a higher volt reading when the bikes running than when it's off. A couple volts + or _ above 2000 or so RPM. Do you have a manual?

Wilkinotti · New Member Joined: Oct 23, 2005 Posts: 4

Yep, I've got both voltmeter and manual. Am I correct to assume that all of the other electrical components will operate solely off of a discharging battery, but the headlight circuit needs to be opened by voltage generated by the alternator?

mo650chopper · Posted: October 26, 2005, 5:05 am Post subject: Re: Headlight Circuit??????

Yes The "Safety Relay" keeps the headlight circuit off untill the engine starts
and then the altenator power closes the relay bringing your headlight on. So
it should be either a bad Safety Relay or a charging system issue.

Wilkinotti · New Member Joined: Oct 23, 2005 Posts: 4

I found that one of the alternator brushes had a broken wire. Obviously, I need to replace it regardless, but would this lead to a charging system failure, or would it just mean the alternator was only about 50% effective?
Using the meter, I found that the readings were the same whether the bike was revved or just idling.

mo650chopper · Posted: October 26, 2005, 7:41 pm Post subject: Re: Headlight Circuit??????

I would assume it would not operate at all with a broken brush wire, As your
results seem to indicate. If it's not a repairable break Mike'sXS has
replacements.

Wilkinotti · New Member Joined: Oct 23, 2005 Posts: 4

I replaced the brushes with some new ones from Mike's, and she's up and running again. However, The backlight on the tachometer (and the high beam indicator) is dead. I'll research this some more, but any input would be helpful.
Thanks!

kingwj · Posted: November 1, 2005, 8:07 pm Post subject: Re: Headlight Circuit??????

check for a broken ground. I found that out the hard way.

mo650chopper · Posted: November 1, 2005, 10:40 pm Post subject: Re: Headlight Circuit??????

As long as everything else, Headlight, charging, Etc. is working properly now
I would check the bulbs or for a lose connection, bad ground. I had to replace the
backlight bulb in my speedo as well as my high beam indicator light on my
80 XS when I first rescued it from the dead.

Gotlieb1 · Posted: November 14, 2005, 1:44 am Post subject: Re: Headlight Circuit??????

I just had similar problem with my 83, and after looking around for a while I found a weakend terminal end in the fuse block. Check your fuse block under the seat by your battery. Don't try to squeaze it with a pliers to improve contact because the little buggers break. I have changed one already with the new style fuses, but not much room. I see Mike sells a new block for $22.00. Hope this helps.

What Happened to 650rider.com?

Yamaha xs650