Bought a new to me trailer

[Big Rick]

to tow behind my Interstate, I am talking with Da Prez about getting a hitch for the bike.
My question is this....is there a premade wiring harness to buy? or will I have to build a wire harness to fit with the flat four connector on the trailer?
I am no electrician, so either way I will be having a friend wire it all up for me 
thanks in advance for any info.....and sorry if this is posted in the wrong category '
   Big Rick

[The emperor has no clothes]

This is what I have been using for years with no problems. It's pretty easy to wire up. Although, I wouldn't use their crimp style connectors. Or any others. I just made up some bullet connectors.

https://www.amazon.com/Hopkins-46255-Power-Taillight-Converter/dp/B000CMKG6O

[sandy]

This is what I have been using for years with no problems. It's pretty easy to wire up. Although, I wouldn't use their crimp style connectors. Or any others. I just made up some bullet connectors.

https://www.amazon.com/Hopkins-46255-Power-Taillight-Converter/dp/B000CMKG6O

Mr. Head's unit is what I used on 2 bikes. Still have one of them. If your trailer is all LED's, this unit isn't the right one. Can't remember the Hopkins number for the LED version.

[MarkT]

Add this circuit to the bike and it powers the trailer lights, LED or incandescent, using a 4-pin flat connector.  If you can follow a diagram and solder or have a friend do it, this is easy.  Bonus, you also get RBT on the rear marker pods (or any other rear signal lights) and you don't have to change the tail light fixtures - 1156 sockets work.  However you should change the bulbs to LED arrays as incandescent make too much heat and will melt the plastic parts inside the pods.  Autozone has them, I got mine from superbrightleds.com  I installed this circuit on Jade and Deerslayer.

[The emperor has no clothes]

Add this circuit to the bike and it powers the trailer lights, LED or incandescent, using a 4-pin flat connector.  If you can follow a diagram and solder or have a friend do it, this is easy.  Bonus, you also get RBT on the rear marker pods (or any other rear signal lights) and you don't have to change the tail light fixtures - 1156 sockets work.  However you should change the bulbs to LED arrays as incandescent make too much heat and will melt the plastic parts inside the pods.  Autozone has them, I got mine from superbrightleds.com  I installed this circuit on Jade and Deerslayer.

just out of curiosity, how many relays do you have total on your 4 bikes ?

[MarkT]

There's 22 (I think) on Jade.  A dozen or so on Deerslayer. I think 2 on George just for the headlight power upgrade.  No extras on Marty which is stored as a parts bike.  They very rarely fail, having bought quality relays, not Chinese junk.  Any failures are usually the connectors slipping off the pins.  I try to give them a squeeze so they have enough friction.

[Ken aka Oil Burner]

I used this from Shoptalk:  http://www.herberts.org/wayne/valk/trailerlights.htm

[Big Rick]

thank you for all the answers guys...I do appreciate them

[Mr Whiskey]

Call Lewis @... 865.219.9192
https://electricalconnection.com/index.php/product/isolator-honda-gl1500/
Pretty sure mine for the Interstate was plug-n-play
Great guy with quality products & customer service!
(not affiliated, jus' very satisfied customer... he jus' fixed all my Wing gremlins couple weeks ago!)