Electrical Problem - No rear light or tag light

Two steps forward and one step back. I got one issue off my plate and now another has come up. My lights are not working properly. My tail light isn't working, but the brake light is fine. The tag light is not working either. The headlight doesn't come on when I turn the key on but only when the bike is running. I found a connector that wasn't plugged in but after some research, I think it's for upgrading the firmware on the dashboard (it's in the same trunk as the ECU connector). The Hazards don't work either. I noticed also the passing switch only works on High Beam and the LED strips on the forks flash with them.

Someone added some Rinzoma LED signals and there is also a pair of LED strips on the forks that are tied to the running lights. I thought all of these were working when i got it so something must have happened at some point but I can't tell what the problem is jiggling harnesses around.

I looked on the diagram and there is a wire that runs across the page from right to left that goes to the headlight from the tail light. Could there be something going on with that? How do you guys troubleshoot an issue light this?

Headlight is working correctly. With the tail and number plate lights I'd start by double checking the connections in the tailpiece. Easiest if you take the rear bodywork/fairing off. There are three plugs under there, the indicators and the tail light which I *think* incorporates the number plate light as well but it may be separate, (I'm on holiday in Queensland and can't check right now.). Make sure when the ignition is on that there is power to the tail light plug.

You could try powering up the LED's in the tail light independently, I have seen light units go bad, but only two in 17 years so I'd hardly say it's a 'Common' issue.

GRiSO doesn't have hazard lights. Flasher sounds like it's working as it should. Adding extraneous stuff like LED strips requires hooking into the loom. Never a good idea. Yes, the second plug near the diagnostic plug is the dash interface.

Thanks Peter!
If the brake light works, wouldn't that mean the tail light is still good?
I really appreciate all the work you do here. When I get my issues sorted out with this bike, I'd like to send you a bottle of scotch or something...

Tony

Sadly no. They are on two different circuits I think?

Roy is a far better source of electrical gremlin info than I am. That's why I usually leave it up to others to answer electrical questions. Something like this should be pretty straightforward though.

I found a blown fuse... Haven't proved it's the cause yet, but likely...

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Tony, good to see you use a multimeter to check fuses - certainly a better method than "it looks OK".

Lol... Thanks! I was going to use it to check voltage but I'll poke around after the fuse is replaced... Don't want to get in the weeds!

I think this is supposed to be a 15amp. Can anyone verify? If so, I'll use that spare right there... Not sure why that yellow one was in there..

I ordered fuses from AF1 also.

Looking at the fuse list on the lid of the fuse holder .. which number fuse has blown?

It was B.

I put the spare 15a in and the lights came on. Now let's see if it blows again.
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Is it the brake or tail light that’s out? I can’t remember? If the brake check where the cable from the switch clips to the frame.

No, the brake light was good... It was the tail light. It's working now but I'm waiting to see if the fuse blows again.

No need to buy fuses from AF1. Any auto parts shop will have them.

Good to know for the future... Does that form factor have a name of some sort? E.g. Auto fuses?

There are many types of auto fuses and fusible links. Just take one of the blown ones to Napa or Pep Boys or whoever and grunt at the spotty youth behind the counter and wait for him to grunt back. I just refer to them as blade fuses.

Roger that!! Thanks!

If it happens again, Tony, there may be a pinched/bruised wire/insulation somewhere aft of the fuses. If so, replace the fuse and wriggle all the harness around and you might find the offending piece. Hopefully it was a one off and will not happen again.

Thanks for chiming in! The bike has these LED strips that are in the same circuit. I may try to delete them next and start over. If that doesn't work I'll take your advice and start running down a short.

Blew another 15 amp fuse. I'll check for shorts on Sunday, but I suspect it's the led strips. Looks like they are plumbed into the headlight somehow. What do you folks think about me upping the fuse from 15 to 20 amp to accommodate them? I wonder if they are pulling enough to just go over 15amps?

The fuse is there to be the weakest link. If you up the fuse size, something else becomes the weak point. Do you want to find out that it's the wiring, or something even harder/more expensive to fix?

yea, you're right... I'll see if I can find a short later today. It's supposed to rain, so it's a good opportunity to hang out in the garage and get a few things off my plate. I hope to get this sorted out soon, hopefully today.

It would be very unusual for 2 working led strips to use as much as 15a. That is enough power for 2 old fashioned headlight bulbs 90w each.

So either a wirung fault ir an internal short in the led?

I think the passing bulb in the headlight is an LED also. I'm not sure if that was by design or after market. The headlamp is incandescent.

Hi Tony,

I just took a peak at the wiring diagram and it looks like a simple circuit. I would first look at the aftermarket add ons.  with no real way of knowing how they are tapped into the bikes wiring, a simple check would be to disconnect these lights and see if the fuse holds.  
if you can't simply remove the non factory wiring from the circuit, be sure to Cap off the  wires with a wire nut or some high quality electrical tape (3m 33 is readily available from lowes and autoparts stores), replace the fuse and run the bike.
while you are tracing the wiring out, try to locate where the previous owner tapped into the circuit. Look for poor connections and the possibility of a stray strand of wire that could possibly short to ground  when the  bike is running/ shaking.

as long as you put everything back to factory conditions, this will eliminate the undocumented aftermarket wiring on your bike. hopefully, this will get you sorted