Trying to set up my Sidekick to tow a small utility trailer.  U-Haul installed the wiring, plug etc. when they installed the hitch.  Basic 4 wire set up.  BUT it doesn't work and a local electrician( here in Mexico) tells me I need some sort of converter to change the Japanese wiring on my car to American wiring on the trailer.
Does anyone know what the heck he's talking about?

yes its a converter that changes the 5/6 wire system that the Suki has to a 3/4 wire system you have to install the converter so it take your rig which has separate turn and brake light  to turn and brake lite are the same which a standard trailer has . the  auto parts store should have them. 

Appreciated!  Do I just ask for a converter to adapter my Suzuki to an American trailer connector?

Yes just ask for the turn signal converter for trailer lights

Amazon, J C Whitney, Ebay, all have then average $23 for the plug and play kit.  Just look for SuZUKI TRAILER WIRING KIT.  Behind the left tail light the plug for trailer wiring is taped to the wiring leading to the tail lights.  I just installed it in my 93 Tracker (using Sidekick kit), and found the wiring plug about 14" further up the tail light wiring loom.  No soldering, crimping, or electrical tape needed.