I can tell you what you will need to install a 5-Way flat connector on your 1999 Harley Electra Glide but we do not have any custom fit wiring harnesses for any motorcycles. Harness # 33525 was designed for a 2005 or 2006 Nissan Frontier.
All you really need is a vehicle side 5-Way connector such as # C58545. All you would need to do is splice in this harness to the appropriate wires on the bike. The white wire is ground, brown is running/tail lights. Yellow is normally left turn signal... view full answer...
I spoke to my contact at B&W and they informed me that the correct B&W Biker Bar Motorcycle Tie-Down System for your Harley Davidson Electra Glide Limited Low is the part # BWMC2301. I have attached a sample installation video for you as well. view full answer...
The vehicle-specific or plug and play vehicle wiring harnesses we offer are for passenger vehicles, not motorcycles so unfortunately we don't offer a plug and play option for your motorcycle.
You mentioned that your bike has four circuits out, which means one for ground, one for taillights, one for right turns, one for left and one for the brake lamp. This is what's referred to as a 'separate' taillight wiring system because the turn signal circuit and brake lamp circuits aren't combined.... view full answer...
Since your Harley isn't one of the standard fits that they have a B and W Biker Bar designed for you would need to use the Custom Frame version part # BWMC2304 which can fit basically any Harley Davidson frame available due to how adjustable it is. This would be the best option for securing a Harley to a trailer.
Since you have a rail trailer you might want to go a different route.
For securing a Harley in a trailer the most popular chock option we have is the Rack'Em Manufacturing Removable... view full answer...
You could use a universal trailer wiring 4-way kit part # 119190KIT to install a 4-way with combined trailer taillight circuits on your Harley Davidson Electra Glide. view full answer...
The B&W Biker Bar Motorcycle Tie-Down System # BWMC2301 referenced in your question is confirmed to fit all model years of the Harley Davidson FL Series Bikes, including your FLHTK.
This tie-down system will do a great job of securing your bike without the need for any straps or chocks. You will simply mount the clamping bar to your bike, drive over the trailer-mounted plate, and your motorcycle will automatically latch into place. The neoprene-lined clamps on the bar won't scratch your... view full answer...