LED tail/brake & license plate bulbs, now I have "Ghost lights" when bike is off?

[Chuck78]

LED tail/brake & license plate bulbs, now I have "Ghost lights" when bike is off?

Anyone experience this before? I installed an LED brake/taillight bulb on a relocated stock taillight (trunk delete, moved light toward seat) & installed a little LED license plate illumination light. Also installed stainless steel mini-gauges with LED indicators in the speedo for oil/brights/neutral/turn signals.

Now after you turn the ignition off, the oil light & neutral light will start glowing, license lamp comes on brightly, & if the headlight switch is on, the taillight glows dimly!!! What the heck?!? Ignition off. Is there moisture inside the ignition switch that is conducting a very minor amount of voltage that slightly illuminates these LED's??? Incandescent turn signals are not affected, neither is the power hungry headlight. Very strange!

The only wiring mess up I did was to wire 2 diodes in backwards for the turn signal single indicator LED on the speedo, which resulted in no voltage passing through to the indicator bulb. I really don't think this could have any effect on this ghost lit LED issue. LED license light was powered off a spare wire in the harness intended for factory running lights, tied into taillight/headlight circuit.

 

[GSCafe]

LEDs change the resistance of the circuit. Try using some resistors inline with the LEDs if you must have LEDs.

 

[GSCafe]

After reading more carefully, no lights should be on with ignition off. Make sure you have tapped switched power only.

 

[posplayr]

Anyone experience this before? I installed an LED brake/taillight bulb on a relocated stock taillight (trunk delete, moved light toward seat) & installed a little LED license plate illumination light. Also installed stainless steel mini-gauges with LED indicators in the speedo for oil/brights/neutral/turn signals.

Now after you turn the ignition off, the oil light & neutral light will start glowing, license lamp comes on brightly, & if the headlight switch is on, the taillight glows dimly!!! What the heck?!? Ignition off. Is there moisture inside the ignition switch that is conducting a very minor amount of voltage that slightly illuminates these LED's??? Incandescent turn signals are not affected, neither is the power hungry headlight. Very strange!

The only wiring mess up I did was to wire 2 diodes in backwards for the turn signal single indicator LED on the speedo, which resulted in no voltage passing through to the indicator bulb. I really don't think this could have any effect on this ghost lit LED issue. LED license light was powered off a spare wire in the harness intended for factory running lights, tied into taillight/headlight circuit.

I would start there; the rest are probably just symptoms of the same problem. That should be pretty easy to figure out. Measure the voltages on both sizes relative to the battery (-).

Obviously with switch off both should be zero. The obviously are different and are forward biasing the LED.

Is your R/R going out? Unplug it.

 

[Chuck78]

Aha... How could a failing regulator-rectifier bleed tiny amounts of voltage into the lighting circuit, as well as the indicator lamps??? It is a replacement of some sort I believe, not an original unit (or 2 separate units, rather). It seemed to be charging well, however. The license plate LED's are several small LED's, that's why they shine brighter. On the schematic, I tied into a wire that goes directly into the taillight, intended as a spare optional running lights lead. I will re-trace the wires to make sure no one else has spliced it somewhere it shouldn't go, but I think I already did that.

The thing is, with incandescent bulbs, none of this happened, because it is just a tiny amount of voltage that is illuminating these LED's. Very strange.I'll troubleshoot once I get my own bike back on thevtoad. This is on the '77 GS550. My bike is fork-less and idles roughly at the moment, higher priorities, but thought I'd inquire on this issue when I had some down time.

 

[posplayr]

Something is apparently supplying voltage to your signal circuit with the key off; you should be able to measure it. If it is there it is either a short to an unswitched wire or inside of the ignition switch or some imaginative wiring or some sort .

This is really quite straightforward and there is really no reason to hypothesize. Put a voltmeter across the burning LED, now start removing things till it goes away (start with the IGN fuse). That will in all likelihood be the source of at least one problem if not all of them.

With that bright of a laight you can probably just use it instead of the voltmeter.

 

[Chuck78]

Procrastinated finding wiring problem, I figured I just had to reconfigure the wiring. Wouldn't start for her today, then noticed smoke coming out of headlight bucket!!!! Connectors on ignition switch & wiring harness were all brittle plastic & corroded wires, crumbled in my hand, that's where the voltage contamination was coming from! Wires were sort of touching each other but not enough to deliver full voltage duevto loosely laying in there & being so covered in green corrosion...

 

[Steve]

Good find :encouragement:

now clean up that mess :-\\\

.

 

[Chuck78]

Not the first ign switch connector I've seen do this on a a GS. I replaced it with 4 pairs of insulated male/female 1/4" connectors for now with plenty of dielectric grease in crimps & blades.

 

[posplayr]

Good find :encouragement:

now clean up that mess :-\\\

.

Wire brush or DeOxit? maybe some fine sand paper.

 

[Chuck78]

Wire brush or DeOxit? maybe some fine sand paper.

The wire strands themselves were green & corroded and I didn't have a spare plastic plug housing! So I just cut them back to good wires & crimped on 1/4" m&fem connectors. Works great now!