Need help with electrical wiring to turn signal

[Rogshap]

I have a 27 foot Wildwood le (2006). I had to replace the electrical plug that goes from a junction box under the RV near the tounge to the truck. When I replaced the wiring, I matched everything as it was...color for color.
Now, I can't get the left turn signal to work. Everything else is fine as it was. How can I find what wire the left turn is...and what it should be connected to on the new umbical cord to my truck?
Thanks.

[caper]

Check out thread for wiring problems.