Hi Guys

For the last four days I’ve been looking for an electrical fault, the headlight stopped working.

This is what I’ve got…

> Rear light, break lights, dash lights, and indicators are all working correctly, except the headlight. But, Hook the bulb up to a battery, works OK

> With the bulb IN the holder - high beam light on the dash is permanently ON with the switch in either position, headlight not working.

> With the bulb OUT the high beam light on the dash works in either position

From the manual I’ve done the following

(A) Continuity test on the switch and it only passes 1 out of 2 tests

Brown and Yellow [PASS] high beam
Brown and Green [FAIL] low beam

(B voltage) Switch at high. With the bulb in the holder, and the switch gear plugged in; using a meter on the holder it does this. + to the yellow (high beam) and – to black I get the correct voltage reading AND the bulb lights up on high

Switch at low + to the green (low beam) and – to black I get the correct voltage reading and the bulb lights on dipped

(C) With the bulb in the holder, and the switch gear unplugged; + to the yellow (high beam) and – to black in the connector block I get NO voltage

At this point I mail Dave Lambeth who say’s “it’s probably not the switch but a damaged wire” So I cut all the shrink wrap away, start looking and find nothing obvious. However, the use of electrical tape on the wires and connection blocks under the tank suggest, someone has been doing stuff.

I figured I’d unplug the back light, fire the bike up, and check if the headlight still worked using the meter as before but, with no backlight inline.

Flat battery, that’s not surprising. I’ve been starting the engine then killing it leaving the lighting circuit on a lot over the last couple days. Charged the battery, pushed the button, didn’t fire. Killed the battery, recharged it, and it’s the same, won’t start.

OK I said to myself, it’s electrical. What stops it starting? So, I tested the side stand, clutch, and neutral switches, all OK.

The one thing I did notice yesterday after the first try was the oil level; I could just see it in the glass, which is unusual when the bikes been stood for a couple weeks. Today when I look, the oil level is right up, as if I’ve just been riding????

Now I’m thinking, FK it’s not electrical

Any suggestions???

Shaun

Fastest test for a short:

Put everything back together.
Undo the negative terminal on the bike.
Set your meter to AMPS on the 10A range.
Test from the battery negative to the unconnected battery lead.
If there is no current gradually drop onto the mA ranges.

If you have no alarm there should be nothing flowing round the circuit. If there is a short you'll see something flowing above 1mA.

Your headlight fault must be electrical. The glowing high beam indicator suggests to me that's in the circuit with the short.

The oil level and not starting (is that not turning over or not firing?) I would say are a different problem.

For multiple electrical faults make sure that battery negative lead to the engine bolt has zero resistance. Earth faults do weird things. A flat battery is usually the first sign as you've been gently warming the frame in most cases. Big load items won't work as they are getting their earth via some tiny lamp element, while the bulbs will be quite happy to glow under the few volts they can get across wires coming from other components about the bike whose drops give enough differential for a current to flow!

Good luck

Andy

The headlamp problem is surely a bad earth somewhere - the strange behaviour of the warning light is a giveaway. I would start with the battery to frame earth connection, and go through every single earth in the lighting circuit, cleaning and refastening. If there are signs of bodgery in the wiring, that would be a good place to start. Check all wires, break and remake all connections, scrape all earth points back to bright metal. Ignore the tail leading to the rear, as that seems to be fine. It's somewhere in the bundle that goes forward from the battery, under the tank and into the headlight area, with the side circuit to the switch.

The failure to start is a separate issue, I think (unless something in the wiring has borked the reg/rec or the CDI unit). As threewheelbonnie says, is it a failure to turn over, or a failure to fire? Big difference

__________________
2006 XT660R daily ride, 1994 XT600E about to be reborn, Blog: http://goingfastgettingnowhere.blogspot.com/

note that wires can also fail inside the insulating cover only (copper truncated and insulation OK), check resistance on every wire pulling it and checking if it's elastic.

__________________
http://www.bikepics.com/members/b4nz4i/

Hi People

Thanks for the answers. Yes I know the headlight is an electrical issue. I was just about to start from the beginning when the battery needed a charge. After the charge it wouldn’t start, so I tested the parts that would stop that (i.e.) side stand, clutch, and neutral switches.

It’s at this point I notice the oil level, this is the bit I was referring to as “not electrical” it’s strange that this is the first time the bike has not started since I got it and, the first time the oil tank has had this level from cold.

I’m now stuck, not a clue why it’s just decided not to start after 13 months? The only clue is the oil level; it always drains to the bottom if it’s not started. And, the light circuit won’t energize until it starts so I’m stuck with two faults

Just to clarify, it does turn over, and when I took the plug out, it did spark.

##UPDATE##
That oil level was coincidental because after a new plug it’s just started Headlight still not working :confused1: thats it for the night, back to the start 2mora

shaun

Half way there, then. That's good

__________________
2006 XT660R daily ride, 1994 XT600E about to be reborn, Blog: http://goingfastgettingnowhere.blogspot.com/

Have you tried just running a bit of spare wire from the Negative battery terminal to the earth on the bulb holder?
Its just a quick simple way to check for a bad earth, By giving it a good earth and seeing what happens.

Also check your getting a good contact from the bulb to the bulb holder,

You did`nt mention the age/mileage of your bike, But mine is 1990 and i`m just starting to get some broken down wiring, Mainly on earth wires,

Pete

Hi Pete

Bike = TT600RE Year 2003

I’ve just run an earth wire from the battery to the bulb holder, still the same, no headlight. But, with the handle-bar switch in my hand and not on the bars, the high beam light on the dash was flashing on-and-off as I moved it about. Now I’m thinking it’s possibly a broken wire, so I’ll have a look and report back.

Shaun

Sounds like you've found it to me.

Andy

I have a TT600RE too, same year, 2003.

and last summer i had a very similar problem as yours.
no headlight, high beam lights on dash ON, etc... after a long time spent trying to understand all the possibilities, it turned out to be the bulb-holder that needed to be replaced.

as per the oil level increasing or decreasing when the bike is not used, it's normal.
the important is to make sure you don't have too much oil in the engine... especially after running it for 20 minutes.

good luck!

Funny you should say that, about two hours before you made that posting I did two tests.

Unplugged the headlight unit
Jammed two bits of wire in the female sockets
Yellow high beam and black neutral
Picked up just the bulb
Touched the wires
LIGHT

With the unplugged the headlight unit, I did this.

Put bulb back in
Red and black wires wrapped round the battery terminals
Touched the correct parts of the bulb and LIGHT
Took the neutral from the bulb and touched the neutral on the holder, nothing

Got a very small screwdriver, and then bent the copper strip that’s moulded in the plastic on the holder out a little. Then I rubbed down the small strip with sand paper round a match stick.

Plugged it all in
Started the bike
LIGHT – high and low

This whole thread was about 1 spark plug and 1 bulb holder

Thanks
Shaun

It's always the little things that get us in the end.

Glad you have sorted it.

__________________
2006 XT660R daily ride, 1994 XT600E about to be reborn, Blog: http://goingfastgettingnowhere.blogspot.com/

Glad its sorted.
Had to do my sidelight today, That was the bulb holder that had gone. Did`nt look corroded, But it was`nt giving a good earth.

Nice one. Glad it's sorted.

Andy