On the subject of the Hoppy convertor: I know a few guys towing trailers with their motorcycles, and all use a Hoppy to run the lights.
I've towed with several Japanese cars, and years ago I just rewired both my trailers to have extra lights on them, just like all Jap cars. (My Canadian-made Pontiac Bonneville is wired like them as well.)
Basically I added one wire and two lights for a brake light circuit. I've done it that way for 27 years, since I bought my first Suburu in 1981. I can still tow with an American car just by using a little pigtail adaptor.
Isn't that cheaper and more fool-proof than a Hoppy?
I haven't made up a pigtail for my Tacoma yet, but I thought I'd ask in case there was some terrific reason to switch both trailers back and use a Hoppy.
Also, I have the Tacoma factory towing package with the round 7-contact plug. I haven't looked at the diagram, but it is the "Asian" system, right? Seperate brakes and turns?
Are there additional fuses to that isolate the factory towing wires under the dash somewhere?