[mcraigor]

Two days after wiring an aftermarket taillight I ran into a small problem.  The running light doesn't seem to illuminate.  I tested the light with a battery and the both the brake connection and running light wire made the light illuminate.  Also the brake light works fine along with the ground wire.  I checked the forward connections until the wiring goes into housing where I did a visual inspection and found no damage.  Everything I tested on the grey running light wire showed zero volts until going into the housing.  Plus, I checked the circuit breaker and everything on the circuit works(turn signals, etc.)

The running light wire is the grey wire on the wiring diagram but the chart is super difficult to decipher(low definition and fuzzy).  Does that gray wire go all the way to the headlight?  From what I can tell there is a connection, "add-on lead for DHL", but then where does that gray wire wire go?  Does it just terminate there?

I was going to pop the headlight tonight and test the connection at the "add-on lead" but I ran out of daylight and thought I would ask the forum to see if someone had the same problem.

[Arizoni]

I don't know about the GT but in the headlight housing on my G5, there is one gray wire.

It's purpose is to be attached to the running light bulb that is in the lower part of the headlight reflector on those old lights that use a small removable headlight bulb (not a sealed beam type).

Because the 7 inch headlight I installed doesn't have that little running light in its reflector, the gray wire went unused until I added a after market voltage indicator.
I used the gray wire to power the indicator.

Because the running light is on when the 'parking lights' or the actual headlight is on, a glance at my voltage indicator tells me if I have turned on at least my parking lights.
If I don't turn on the parking lights or headlight when the engine is running, the voltage meter is not lit.

Link to the voltage indicator I installed.

https://forum.classicmotorworks.com/index.php/topic,12424.msg137999.html#msg137999

[mcraigor]

lol, I was hoping that flipping the switch for the headlight/running lights would work but sadly I tried that last night.  Today I noticed the headlight was out.  I don't generally ride at night plus headlights aren't required in Illinois during the daytime, as far as I know.  Looks like my turn signals all work but the headlight and rear brake running light does not.  The brake light illuminates at both the rear brake and front brake. 

I'm a bit for a loss but I assume that means the switch on the right handlebars isn't connecting but I am not sure.

[mcraigor]

Well, I found a couple dirty spots and then a loose connection.  Once that was all solved up I still was boggled but I guess during all the searching I set off a circuit breaker.  Running lights restored.

[hpwaco]

Do newer GTs have " circuit breakers " ?  My 14  only has fuses - unless I'm missed something.  Tnx, hp

[mcraigor]

Do newer GTs have " circuit breakers " ?  My 14  only has fuses - unless I'm missed something.  Tnx, hp

nope, my mistake.  I was doing some house wiring recently and had circuit breakers on the mind.  There are only fuses.  Turns out when I wired my new taillight if you wire the brake light or running light in reverse it will set the fuse off.  Anyways, I'm on the road with a side mounted license plate/taillight combo that works without tearing through my license plate.