Lockup Torque converterwahamilton87 said:
http://www.phoenixtrans.com/html/lockuplowdown.pdf
All stock converters slip around 200-300rpms at cruise speed etc.. The TC with a lockup clutch inside is similar to a Manual tran's clutch. Eliminates the slippage.
It doesn't have to be connected to shift right but, if it's not it may cause the trans to overheat.
Autozone's website has wiring schematics in there trouble shooting area.
http://www.73-87.com/7387garage/drivetrain/lockup.htm