I ride a 2001 HD Ultra Classic and it has a 6 pin rectangle plug wiring harness. I recently bought a tag-a-long trailer that has a 4 pin flat plug. Is there an adapter to allow there two plugs to connect?

 

I have a similar problem.
One of my bikes has the five wire flat connector, while the other has a six wire rectangular one.
My tow along trailer, has a five wire flat as well.
Do they make adaptors for six wire rectangular plugs, into five wire flat tariler side plugs?

 

Yes they make adapters to go from 5 to 4 6 to 4 and 6 to 5 in Flat to Rectangle and Round. Just hit a trailer store and you should find what you need.

for wiring diagrams http://www.etrailer.com/faq-wiring.aspx

For best and safest results on our harleys, I use a "powered" 5 to 4 wire converter made by Hoppy # 46255 that I picked up from PepBoys.


This is the trailer I use http://www.harborfreight.com/600-lb-...ler-66771.html