Confusing electrical issue - indicator, horn and light issues

S

Sideswipe

Active Member
<<Update!! The indicators flash, but still all 4 not just left or right!)

Hello!

I have been having no end of trouble getting my indicators, horn and headlight to work. it's on a 1979 Honda XL250S Currently here's where Im at:

horn button doesnt work
turning indicators to the left or right and both sides flash
headlight wont turn on at all.

Here's what ive tried, and some details about the bike:

I tried using a cheap aftermarket indicator control from ebay - with this the horn worked, but nothing else. I suspect because it was wired quite differently to the stock honda kit (there was no green wire(ground)input to the control)

I have a LED blinker relay

i have tried bridging the black wire along with the various ones from the plug. bridging to either light blue or orange (left and right indicator) turns all 4 indicators on with flashing bridging the horn deafens everyone in a 1km radius.

I have gone through the wiring - the only thing i can find is that there is a switch on the Kill switch control with the options of P, H, or a . opening up this control showed a white wire with a yellow stripe was not connected which the wiring diagram shows is related to the headlight switch (and may be the headlight's issue).

I have no idea what the 3 options do, but switching it between them made no difference to the indicators.
 
Get a wiring schematic for your bike. They aren't that complicated for old trail bikes.

What sort of indicator relay do you have? LED indicators require a "no-load" relay....otherwise the lights wont flash.
 
Ive got the wiring schematic, thats how I worked out I was missing a voltage regulator ;)

not too sure with the relay is there a way to check (i have a multi meter)
 
Lets take it one circuit at a time. When you're facing multiple issues, trying to solve them all at once (especially if you're unfamiliar with electrical work) is not a good way to ensure success.

If you don't have a multimeter, get one.

Lets do the horn first, since that's usually pretty easy.

The horn, itself, should have two wires going to it, usually with spade connectors. In the XL250, one wire is for ground (dark green) and the other wire is power from the horn button (light green, usually referred to as mint green in the Honda manuals).

Check the dark green wire with your multimeter to ensure you have continuity to ground.

Now work your way back to the horn button on the control bars. If you peek inside the control, you can usually see the two wires that are soldered to the horn switch. On the stock controls this will be black and that light green wire from earlier.

Unplug the black wire from the harness and test continuity between it and the light green wire. You should get nothing. Press the horn button while continuing to measure and you should now have continuity.

The final test should be with the ignition switch on. Setting your meter to 20VDC, check to see if you have voltage on the black wire that's going to the horn button. You should have a little over 12V (I think XL250 is 12V, right?).
 
Generally you would start with the thing that makes the electricity
 
The 6V DC is function of the regulator. The Stator prolly makes about 40V AC.... Funny thing is, the alternator is a current generator, not volts.....6 volts requires more current than 12V, so the stator is probably the same capacity, all in all, as a 12V unit.
 
Yeh from my understanding leaving the stator at 6V, my only disadvantage is it may not charge my battery very well. It will be converted to 12v too but the bloke that does rewinds on the NSW central Coast is our of office till June. but I'm led to believe it should not be an issue here.
 
Sideswipe said:
Yeh from my understanding leaving the stator at 6V, my only disadvantage is it may not charge my battery very well. It will be converted to 12v too but the bloke that does rewinds on the NSW central Coast is our of office till June. but I'm led to believe it should not be an issue here.
Click to expand...

I'm afraid your understanding is not entirely correct. Voltage increases as RPMs increase. There is no such thing as a 6V stator or 12V stator. Alternators are usually measured by their current rating (the number of amps generated at 6,000 RPM of rotor speed). This number usually includes a specific voltage as well (usually 13.5) because voltage and current are related.
 
To add to Sonreir's post, if you short the alternator output, at the time is is producing say 5 amps, the voltage will be zero, but the amps will still be 5 amps.

But don't short the alternator/stator.

The alternator produces AC current. Voltage depends on system resistance. The regulator watches the 12V side and lowers the resistance through an SCR to ground, to make sure the DC volts don't exceed the rated max.

A 35 watt 6V light at 6 volts requires 5.8 Amps. A 35W 12V light at 12V requires 2.9 amps. So an alternator on a 6 volt system has to generate more current for the same amount of light then an alternator on a 12V system.
 
In other words your old stator should work with a 12v reg/rec.

Your problems are wiring related.

Go back to your wiring diagram, make half a dozen photocopies of it and start with each individual circuit. Highlight the horn wiring only on one of the photocopies. Understand what the colours are, how it's wired and how the switch works. Then make sure it works. Then move on to the next one.

It really is just a methodical approach that you need to take - trying to fix everything at once will fry your brain.
 
Hillsy, thanks for the summary.....Someone once said about me: "don't ask him what time it is, he will tell you how the clock works" 8)
 
Thanks for the info guys!!

slowly working my way through it - got the brake light "working" HUZZAH!!

the issue with it is no longer electrical - the Front brake lever doesn't swing back far enough to hit the switch in it's little casing and turn the light off :mad: back brake is perfect, front brake you pull the lever, light turns on, let it go, light stays on, push it forward, light turns off. if i try tighten the brake cable, the brakes are on even when you're not holding the lever, so frustrating.
 
There is certainly a spring. It does spring back most of the way I'll have a look at it as I do have a spare hub although I don't envy the thought of swapping the springs over (the other hub has a rooted speedo sensor thing bit hole stuff)
 
I meant spring on the cable as well as the shoes. A bit like this:


-font-b-Throttle-b-font-Cable-Choke-Cable-Front-Brake-Cable-Rear-Brake-Cable-for.jpg


That's a PW50, but the spring on the end of the cable keeps the cable tight enough to hold the lever out.
 
So Ive worked slowly but surely with the issues and have resolved the brake light problems, and have had a change in the indicator issue. now they flash, but all 4 flash regardless of whether i switch left or right. still having headlight and horn issues. I noticed disassembling the kill switch there is a white/yellow wire that is not connected to the switch which might effect the headlight, but Im unsure. there's three options on it (P,H and .) but I havent noticed any of the options effect the indicators
 
I think I've worked it out. I believe I need diodes on the left/right indicator wires that go into my "turn signal" light on the instrument cluster to prevent the watts from 'spilling over' to the other side.

some top shelf electrical jargon there

I will resolder the yellow/white wire on the killswitch control and HOPEFULLY that will sort out the headlight.... then it's just the horn that's left. huzzah!
 
Ok headlight is sorted.. now it's just the horn...... why wont it work damnit lol ill take the switch apart and see how we go
 
Test the horn on 12V first with jumpers. If the horn doesn;t work, you may be fiddling with wires you didn't need to.

Also, there is usually an adjustment screw (usually has a lock nut too) that can often get a non-functioning horn into a functioning one.
 
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