I posted this on another thread, but figured this may help others.
http://www.zoro.com/reese-tail-light-converter-78016/i/G7569256/?gclid=CjwKEAiAp_WyBRD37bGB_ZO9qAYSJAA72Ikg4_7TP14un6PGrCLdNVHFNFTFJiUp4oV0ys2g9pjOyxoCKjHw_wcB&gclsrc=aw.ds
I see no reason why this wouldn't work on the ST, I have to use them on my Jeep because the stock system doesn't handle trailer lights well. Basically, all the power is fed from the tow vehicle battery, you tap the running, brake and turn signals(under the seat on the ST), the converter only uses a signal from each tap, meaning there is not a large amount of current draw from the stock wiring, the power is pulled direct from battery. I've used these with incandescent and LED bulb systems. I've almost got the missus convinced to let me get a tag-along for the 13(HF has theirs on sale....), it would give us enough room for her stuff on weekend trips..........
They wire in pretty easily, of course, on the Jeep I had to run a wire from the engine bay to the back.....
http://www.zoro.com/reese-tail-light-converter-78016/i/G7569256/?gclid=CjwKEAiAp_WyBRD37bGB_ZO9qAYSJAA72Ikg4_7TP14un6PGrCLdNVHFNFTFJiUp4oV0ys2g9pjOyxoCKjHw_wcB&gclsrc=aw.ds
I see no reason why this wouldn't work on the ST, I have to use them on my Jeep because the stock system doesn't handle trailer lights well. Basically, all the power is fed from the tow vehicle battery, you tap the running, brake and turn signals(under the seat on the ST), the converter only uses a signal from each tap, meaning there is not a large amount of current draw from the stock wiring, the power is pulled direct from battery. I've used these with incandescent and LED bulb systems. I've almost got the missus convinced to let me get a tag-along for the 13(HF has theirs on sale....), it would give us enough room for her stuff on weekend trips..........
They wire in pretty easily, of course, on the Jeep I had to run a wire from the engine bay to the back.....