I'm stuck on this one
 

So I'm still riding my 2012 Triglide. The right side tail light stays lit while we are running, but neither the turn signal nor the brake light works. I am really scratching my head on this one. Anybody got any ideas? While we were looking for the original problem, which was the tail light was out, I found 2 blown 15 amp fuses. Thought I fixed the problem...wrong!

If its an 1157 bulb one of the filaments is burnt out...They have two in the bulb one is for the brake/turn light, The other is the running light...

Thanks for your advice, Rhino. I replaced the old bulb, a 3157, with a new one and got the same thing happening. Tail light on, no brake light, no signal light. Next I tried to swap the small wiring harnesses that the bulb is connected to. I put the right on the left and the left on the right. Still had no turn signals or brake light on the right. So, now I've eliminated the bulb and the small socket wiring harness as the problem. Where should I look next????

Possibly a connector for rear wiring harness under seat? I will keep you in my prayers. Fred

May sound strange, but unplug the bulb on the other side and see if the one having trouble comes on. Also pull the right front one if pulling the other one doesn't do anything.
Another test is to measure ohms from the bulb ground to a good grounding point. Then have someone hold the brake and check for 12v on the socket withe the bulb out. Careful not to short anything.

Did it start happening after you hooked up the trailer lights?? There are 2 connectors under the seat that are nearly identical. I ran into this when hooking up lights to wife's accessory lights on her luggage rack. Good Luck

Thanks for the suggestion to check the rear harness under the seat, Fred. I tried it---DRAT!!! No luck. So, then, I tried a couple of suggestions from lah2420. Thanks for the thoughts, but again, no luck. I removed the front light bulb, nothing changed, then I removed the bulb on the other side, same result. I've got to confess, though, that I'm not very good with a multimeter and I'm not sure I did what you said to do correctly.Then I got to Screwball's suggestion. Again I want to thank you for your input. Unfortunately, we have put over 30,000 miles pulling that trailer behind us with that same connection. Also, the trailer signal, brake, and running lights work. As I'm writing this I'm thinking more about what lah2420 said and I think I need to check the wiring from the light socket harness back to the connector under the seat.

look for a pinched spot or a worn spot on the wire under the trunk.

Thanks for your suggestion, Rockhard. I spent quite a while this morning(2 hours) looking at and feeling wires looking for any signs of chafing. No luck.I also unhooked the trailer wiring harness to see if that would make any difference. Nope, same problem. I also took apart the rear taillight assembly to inspect the pin connectors on the circuit board, no sign of any arcing. My next step is to find somebody who can show me how to use my multimeter to do the type of testing that lah talked about. Also, I keep looking at a lighting relay in the fuse block. What does it do and could it be the cause of my problem? I keep getting the feeling that when I find the problem it's going to be something simple like a bad ground.

Wow, one of those mystery things! Here's another idea, if you've had the seat off recently, it's pretty easy to get some of that wiring pinched between the frame and the seat hold down screw flange; just another place to look. I've got to make sure to push them out of the way before screwing the seat back down every time.