With your guidance, I'm making headway. I tried disconnecting as many plugs as possible without a clue as to if they tied into this circuit and then plugged them back in one by one. Looks like the problem has something to do with the Tour-Pak. I can get all the lights back except the running lights on the Tour-Pak and the rear turn signal running lights. Front and rear fender, tail light, front turn signal running lights and all turn signals work.

Can anyone tell me what there this plug goes, and how do I take it to the next step to identify what is shorting out? In the picture, it's the bigger plug that is not disconnected. (The smaller one was already disconnected and must be for some available option that is not is use.) Large plug disconnected, I get about 90% of my light back... plugged in... POP!

Would the next be to pull out the metal baseplate in the Tour-Pak or back-track the wiring closer to the fuse box?

Again, thank you...

All good advice. Remember when fuse blows immediately it means it is sorting to ground somewhere in that circuit. Pain in the neck to find sometimes. Try the easy stuff first. Unplug lights and then try it. If it stays on start plugging them in one at a time until it blows.

Voltage regulator? I blew some passing light bulbs before I had mine warranty replaced.

Looks like I got it, at least until the fuse blows again!

As I reconnected the plugs one by one into the wiring harness, it turned out to be at the back of the bike and ultimately traced it to the tail / brake lights in the Tour-Pak. I can't explain when I got to this area why the fuse quit blowing, but it allowed me to see that one bulb was running in tail light mode, the other one had the tail light and brake light on with no brakes applied. Switched the bulbs with each other and the problem switched with it. Bought new bulbs and at least for the moment, no blown fuse and the lights are working correctly in 'tail light' mode and then brake light mode when the brakes are applied.

One thing I did notice is that when I went to pull out these bulbs and reconnect the plug to see if the fuse would blow, the bulbs pulled straight out, even though I should have had to give them a slight push in and a twist. From the factory, the bulbs were only inserted straight-in and not turned to keep them securely in place. I don't know if thats what caused the problem or not, but a lack of quality control on Harley's part. Kind of pisses me off that I had to spend the entire day doing this because someone didn't give the bulbs a twist when building the bike and the fact that without the help here, I could have easily blown a couple of hundred bucks having this diagnosed and repaired. (Our labor rate here is $95 per hour.)

On the other hand, if the fuse blows again, then I apologize to the Harley bulb installer!

And I would like to say, once again, thanks for all the help in getting this sorted out!

Glad you got it sorted out and working, gives you some bonding time with your bike to learn it. I dont know if you have a service manual and electrical manual or not but they are the BEST investments you can make for your bike, round 60 each from dealer, they will help you bond with your bike and save you MUCHO $$$$ if you can turn a wrench. If you have limited skills turning wrenches, invest in a bike jack, 2nd BEST investment you can make and start learning. You will be surprised how easy they are to work on. If you already have the manuals and a jack, I stand corrected, lmao!! As you already know, if you run into something that stumps you, there is VAST knowledge on this forum, I guarantee that you will not have a problem that has not been experienced by someone reading these pages. Good luck with your ride, stay safe.

Thanks my67pnycar6;

I do have the service manual, parts manual and jack. Unfortunately, having manuals and being able to read, understand them and implement the instructions is a different thing for someone like me that owns both SAE and metric crescent wrenches! I'm one of those guys that even the most minor repair, I always break something, lose a nut or bolt, take three trips to the hardware store for one part that I didn't need in the first place and generally make things worse than before I started.

Whoa! $40 and hour? Are you in a time warp? Try $90 and hour plus their bogus "shop supplies" percentage. A couple of hours and you're out $200!