Stop Lamp gauge light on when Headlight is on??

[GeorgeOC]

Hello everyone, I am reaching out, hopeful for a little advice on this one. Recently this issue popped up. When I turned on my headlights, my stop lamp indicator on the gauges lit up, and remained on as long as the headlight was on. I also do not have tail light while braking function when headlight is on. If I turn off the headlight, brake indication returns, and the stop lamp indicator turns off. Basically, I have a problem if I need to use my headlights. Not ideal now dusk coming at 5pm and earlier for a few months.

So far, I found a thread from early 2016 with a member's 79' that seemed to have a same issue. Looks like that was addressed through inspecting grounds. I have checked all the ground on in the head lamp bucket, as well as the tail light, all check out ok with the meter. I have replaced the rear tail light, which seemed to have a knackered filament, and a gray shadowing on one side of the bulb. All the connections inside the bucket seem to be ok.

Seems there may be a short somewhere. But where oh where! Just thought I would throw this out there, before I wholesale tear into my headlamp nest for attempt to redo everything!

 

[Brassneck]

Based on what you're experiencing...it sounds like there's and issue with the switch and or wiring to either the running light portion of your tail light or the brake light portion (or both?)....but it could be a few other things.

First things first: Is this a stock bike with stock wiring? Did this just start happening without anything else occuring? Meaning, you haven't done anything to the electrical/brake light switch/headlight/wiring/bulb or anything else and it was working fine before? Or did you do something prior, and perhaps are now just noticing it?

Check the easy stuff first: I would check to make sure you have a dual filament bulb in there. If it's a single filament, then the brake and running light will be one in the same and you're stop lamp indicator could act as if you're running light/brake light isn't working.

Assuming the correct bulb is there, and that's not the issue...If it were my bike, I would start at the back...disconnect the three wires off the brake light and test the two hot leads individually while grounding the third, using jumper wires to a 12v source. Does the brake light work as it should? (One wire will be the running light--and not as bright, and obviously one will be the brake light--and much brighter). If they all work, then work your way to the brake light at the foot. Disconnect the leads going to the foot switch, and connect to a 12v source...activating the switch should give you a brake light. If that works, head up to the handlebar switch...do the same...and then work your way to the headlight switch...you'll probably need to figure out which one triggers the running light, but following the wires in there shouldn't be too hard. (I can't recall the color...maybe yellow?)...having a schematic of your bike will help here.

Anyway, you get the idea....isolate each segment to figure out if it's working properly, then move on to the next.

Hope this helps a bit. Good luck!

 

[TwoManyXS1Bs]

George, what you're describing is similar to "floating ground" wierdness. You could take your meter, on volts, clip the black (-) lead to battery neg (-), then turn stuff on, and with the meter's red (+) lead, probe all the neg connections, including bulb bases. Ideally, with good grounds, the voltage between a probed ground and battery neg should be zero. If not, you've found a floating ground, where the current from some device backfeeds thru other things, as though they're connected in series...

 

[xjwmx]

I also do not have tail light while braking function when headlight is on. !

Does this mean the tail light stays on, but doesn't respond to the brake? If so, probably the brake light is lit along with the tail light the whole time the headlight is on (and dashboard brake indicator is on).

I'd remove the headlight and clip an ohmmeter on its wire and clip the other lead on the brake light, and expect to see a low resistance. Then it's a matter of tracing those wires and discovering where they're shorted. Could be abraded insulation underneath tape in the harness. Or could be a P.O.'s aged bad splicing somewhere. Also, along the lines of what 2M was saying, I'd also check the ground side of the lights that aren't supposed to be on and make sure they're at ground.