The trigger for models produced after 1990 should fit.
When you replace a trigger a new hand will need to be fitted to the gun unless you get lucky and the hand off the old trigger fits and turns the cylinder for correct timing.
A trigger can be bought from gunpartscorp or on ebay.
Call Gunpartscorp,aka Numrich,to get the correct part
Triggers have different widths and are smooth or serrated.
Perfect, I know a fellow Texan would have the answer for me. I found the 686 and 686Plus on Numrich, but the one that looks closest to the existing trigger is for a 686-5 MIM from Midway. I'll give is a shot.
Why does it need a new trigger? That gun has the lifetime warranty and S&W will replace it at no cost if its defective. On the other hand, if screwed up by bubba, S&W might still replace it. Depends on the who you get on the phone.