I have a 2014 Seneca and have some information, perhaps it will be of help. I just had to replace my awning arms due to storm damage, since it happened away from home I had to completely remove the awning in its entirety so we could finish our vacation (without shade of course), and replace the arms and reinstall the awning once we got back home. Just finished yesterday! Replaced the original Travel'r arms with Eclipse arms, quite a bit more substantial in their construction. I also put in the 3-setting Direct Response Electronics to automatically stow the awning when it senses wind, but I will also be more proactive in stowing it before the wind comes from now on.
My awning LED power cord runs in a sewn-in pocket running along the front edge of the awning fabric. Both power and ground there in a single cable, very small conductors probably 22 gauge. They go into the awning tube itself through an oblong hole in the tube with a plastic grommet to keep the tube from cutting the wire. There is a wire disconnect plug stuffed in there to disconnect the power cable from the LED strip itself. The LED strip has the mating disconnect end that goes into the center of the tube through an opening in the slot, covered up by the slot covers when they are in place. The slot covers are black plastic strips about 1 foot long at each end to "fill-in" each end of the slot since the original LED strip is not as long as the awning tube itself. This slot strip is held on by going under the awning tube end caps and also snaps into the tube. But very easy to pop strip out when you need to. The LED strip is held in the tube by an adhesive backing on the strip. Just pull it loose, but doing so may damage the strip according to others. But if you are replacing it anyway....
If you need 3 wires to operate colored LEDs changing the awning power wire wouldn't be too hard in the awning fabric, you could use the existing wire to pull the new wire through. But running the three new wires into the RV would be much more of a challenge. I myself did have to run all new wires since I just cut them to get my awning off the RV.
To replace these wires there is a "conduit" of sorts from inside the back of the control panel (containing my front slideout switches, tank monitor, generator panel, levelers panel, etc.) up to the top of the front awning arm. At least this is how my TS is configured. I took the panel off (watch out for the rat's nest of wiring there!) and then I could access the lower end of that channel. Got in there to run my new awning wires and new small gauge power and ground wires up to the awning itself. Outside at the top of the front arm is where I spliced into the wire going through the awning end seam. You have to leave a loop of wire at the top since it has to flex and move to allow the awning to be wrapped by the Uniguard cover when the awning closes.
I thought I have seen where Carefree's colored awning lights still just use just a power and ground wire. Maybe this is because you may not be able to change the light colors on that strip. Perhaps the color-changing function requires the third wire. That part I do not know.
2014 Seneca 37TS
Toads: 2014 Ford Explorer Sport or 2013 Ford Focus ST