Topic: '79 Honda XL250S...headlight circuit problem

[ron.cieri.313]

Hi everyone...looking for help with my new '79 Honda XL250S...she's in great shape (4,000 miles) and I have everything in working order except for the headlight.  The old headlight just worked on high beam.  So I bought I new headlight, installed, and nothing...check the new headlight by hooking directly to the small 6V battery and it works fine.

Checked for continuity as instructed in other posts here related to my 750 and there is continuity.  Checked for voltage on the same circuits and found almost none.

I've been working my way back through the circuits and its really hit and miss on voltage at the major 6 or 8 prong connectors.  Same with continuity...should there be voltage and continuity on all connection or just when I check between certain wires...I know, this maybe an impossible question to answer with a wiring diagram...which I have...I'm just at a loss on electrical issues.

The battery is giving off 6V as its suppose...that much I can check...maybe I'll work my way forward and see what i find...any tips would be greatly appreciated...thx, ron.

[bryanj]

I think the headlight runs direct from the generator not off the battery

[cb650]

My only other guess would be the switch.

[ron.cieri.313]

...some pics...have a wiring diagram i will scan and post soon.

[cb650]

Its a POS you need to give it to me        No very nice looking.  I used to have a 79 185.

[ron.cieri.313]

Lol, yes she is...its funny the more you buy these things, the better you get at selecting a good one.

I've attached a visual and per Bill's email, have a lead...no pun intended

[bryanj]

Yes it has a battery,rectifier etc BUT the headlamp does not usually run from those only the brake light, horn and indicators

[ron.cieri.313]

Yep, Bill gave the heads up over the weekend after reviewing the wiring diagram (thanks bill again)...the alternator has to be turning for the headlight to be powered...soooooo, she works, well, the high beam at least, the cheap new headlight's low beam blew out again (wasn't working on the old bulb either)...but I have a high beam headlight in cased in a new headlight shell (the old one was cracked)...so I'm quite happy...thanks all.

The only significant problem is the turn signals.  When I bought the bike a couple months ago, the seller or PO had taken the front and rear turn signals off...probably cuz one was cracked.  I replaced the lens on the signal and reinstalled and re-wired.  On the cracked, left rear signal, the ground wire was also missing so I replaced the metal o-ring onto a ground wire and re-attached.  The problem is they don't blink.  When I flip the switch for the left lights, front and rear, light up but don't blink....same with the right ones.  So, I bought a proper signal relay for the Honda dealer but still no luck.

...any ideas?...thx, ron.

[bryanj]

Check the voltage at the battery as blinkers wont unless battery is good and well charged---It dont charge well on the bike as its not a big charging coil.

As to the headlamp check the voltage with the engine running NOTE:----SET THE METER TO AC FOR THIS TEST. I had to fit heavy duty resistors in parallel on a 185 to stop the voltage climbing and blowing bulbs ALSO make sure you fit the original wattage type bulb as you cant alter these without problems. Switch is also odd as it turns on both beams first then one off as you go from low to high rather than one off then other on as this also stops the voltage climbing to excess

[ron.cieri.313]

Ah, thx Brian...I have a small trickle charger on it now.

My replacement headlight came from Thailand so goodness knows if it was the right wattage...for now, I rely on the high beam which i have pointed down so as not to blind anyone but its a pretty small light as you know anyways.

The turn signals bug me a bit but I'll fully charge and try again.

[bryanj]

Will still need engine running even with charged battery

[ron.cieri.313]

Well, left the smal 6V battery on my small trickle charger to long and burnt it's little brains out apparently...replaced the fuse but still no continuity between the poles...time for a new battery i guess?...darn.  Funny though, how can I get a voltage reading from the battery (around 6.3V) but no continuity?...either way, its definitely no longer provide a spark cuz the bike won't start.

...thx, for the heads up on the engine running. for the turn signals blinking.

[scunny]

I've got the same bike(not as shiny) doesn't have lights so no battery, still starts.

[ron.cieri.313]

Well, i replaced the battery ($20) and she starts today so maybe a coincidence? but I'll be paying close attention to how she does over the next couple weeks...no more fixing for awhile, just test riding.

[scunny]

enjoy it, if you get the chance try a 23inch front, helps us older guys stay on.

[ron.cieri.313]

yep, it has a brand new knobby 23" front and 18" back...looks like your riding a mini-chopper or something

[ron.cieri.313]

Another question...after running great, I'm developing a hard starting problem...checked the spark plug and replaced, gas flow, check, air filter clean...i just kick and kick...and she doesn't "catch"...oh, and replaced the battery I thought I burned out by overcharging...now I'm starting to wonder...there is a crack, a physical crack on the plastic housing of the ignition coils???...what do you think...I'm checking everything again tonight...its been really cold year but still, doesn't sound like the problem...let me know..thx all...ron.

[ron.cieri.313]

quick update...not an electrical problem at all...at least with regards to cold starting...that was a choke problem!.  The cable with pulls on the choke arm must not have been closing the choke all the way...cuz when i do it manually, she starts, no probs.

Unfortunately, my enthusiasm during the investigation got the better of me and i yanked on the cable to hard and jammed the little plunger mechanism on top...ah well, i know what the problem is now and new cable on the way.