CON-FUSE-SION

[RockOn]

While trying to figure out how to add an additional tail/brake light to the luggage rack on my '15 Rocket Roadster, ABS, I discovered I do not have an operating tail and license plate light. Just before that I discovered that one of the previous two owners had cut the wiring to the cheapest plastic saddlebags that were ever created. I trashed the bags immediately when I got the bike but noticed they had non-functional running lights and/or brakes lights at the the backside of each bag. Now, discovering why the bag light were not functional I disconnected the cut/disconnected wires connected to two harnesses behind the right side panel. Later I noticed I had no tail light and wondered if the disconnected saddlebag wires had anything to do do with no tail light. So, of course I got a sick feeling in my stomach that maybe I had done something to cause that tail light failure by disconnecting the wires that led to nowhere. I reconnected the wires and still no tail or license plate lights. That also had me wondering if I had a working tail light when I first got the bike. Maybe not. I knew the brake light and turn signals and every other light on the bike worked but wasn't certain about the tail light. At 78 years old you can't be sure of anything.

Anyway, thanks to Herm and other commentators I found in my search for clues I was zeroed in on fuse #10 for, "position lights". Turns out that fuse is blown. Why? I also noticed in position 8 in the fuse box there is a 10 amp fuse and it is supposed to be a 5 amp fuse. It is for gauge lights and also position lights, whatever those are. Why a 10 amp in a 5 amp position?

I am curious about a couple things: Why does the 5 amp fuse, position #10 for, "position lights" get blown and why is a 5 amp fuse, position #8, replaced with a 10 amp fuse for gauge lights and other, "position lights" not covered by fuse #10? I was about to faint working in the garage when it hit 98 degrees. Thanks to that I haven't installed a new 5 amp fuse in position #10 yet but will when I can tolerate the heat, maybe early tomorrow.

PS I spent a good 15 minutes just trying to see if the 5 amp fuse was good or bad. Only under a bright LED light at an angle could I get a clue there was a gap in the fuse element.

 

[Rick111]

Sounds like a nest of vipers . Stay cool keep hydrated !
Happy motoring .

 

[atomsplitter]

Chasing electrical gremlins has all the joy and pleasure of a self-inflicted vasectomy.

 

[TURBO200R4]

first of all a twelve volt test light is your best friend.
hook the clamp to positive and with the ignition in run position place the probe on each side of each fuse.
if you are on the incoming wire it will light up and if the fuse is blown it will not light up.
i will just put this out there if you have the license plate bolts with the lights in the bolts they are junk they like to short out and blow fuses.
i would try to replace the fuses and if they blow then that is the circuit you have trouble with.
you can use multimeter to check the circuits 0 ohms means shorted circuit.
look under fender and check wiring for shorts sometimes the tire rubs the wiring going to the tail/brake light.
only one cup of coffee/tea or that heat will get you.

 

[RockOn]

Yup, exactly right. I knew that was a way to test the fuse by touching those tiny metal pinpoints on top of the fuse but instead I wanted to eyeball that miserably tiny fuse. So, I pulled it and wasted time trying to see inside the fuse with various lights and finally could see a very small gap in the element near the very top of the fuse. I replaced that blown 5 amp fuse with a fuse with an element inside that is much easier to see. It has an upside down U-shaped wire that goes directly across from the bottom fuse blades and easily seen. New fuse in and I've got my tail light and plate light back this morning! Thanks to you Herm for one of your past posts pointing me to position 10 in the fuse box for the tail and plate light.

Now I want to go back to the thing I wanted to do before getting sidetracked by this blown fuse. I am wondering if I can add a LED brake/tail light to my luggage rack by splicing into the wires under the rear fender that go directly to the dual filament 1147 bulb which lights up the tail and brake lights. I know it is a very tight space between the bulb holder wires and the rear tire. If theoretically feasible I'd rather attempt that than messing with any of the wiring under the side panels. Attaching photos of the working tail and plate lights and the new LED tail/brake light gizmo I'd like to attach to my luggage rack. I function tested the LED lights by poking the wires into my battery tender pigtail attached to the battery. Clever, eh?

 

[TURBO200R4]

there is an old electrical saying that the current will take the path of least resistance so that may not work

 

[RockOn]

I will keep that in mind, thanks.

 

[Rick111]

Beyond my meager realm of comprehension. Following for insight on electrical.

 

[Ransom]

Not sure if applies in this case but many had trouble when the stock headlights were replaced with LED units. It's not necessary to remove the position light socket, just the bulb. But this allows the contacts in socket to touch and short circuit

 

[RockOn]

Not sure if applies in this case but many had trouble when the stock headlights were replaced with LED units. It's not necessary to remove the position light socket, just the bulb. But this allows the contacts in socket to touch and short circuit

I removed those bulbs when I installed LED headlights several months ago but now wish I had put an insulator between the contacts and taped them up.