Th350C lockup wiring - G3 GM if you want a light in lock up... use a light in circuit with the 12 volt feed and use the switch on the 12 volt side. turn the switch on, you have lock up and a light too But type this into google "th350C lockup wiring" You should find what you need. You will need a switch and a light would help as well. help wiring lockup on th350c | NastyZ28 help wiring lockup on th350c Jun 25, 2003 Location: parrottsville tennessee usa. i have a turbo 350c and i was wanting to hook up the lockup function. ive already put in a new lockup selonoid. ive searched threads on about every forum site i can find dealin with 1980s gm I haven't done a 350C but I have wired a couple of 200-4R lock-up Re-hook up of lock up converter - 73-87ChevyTrucks Re-hook up of lock up converter. 1 Welcome, Guest. Please (turbo 350c) are still there but not hooked up for the lock up torque converter to do The engine had been switched out for an older 350 and the transmission is now just a regular 350. Is your tranny still a lock up tranny? Might have been replaced at some point. Logged