I HAVE A 1988 FORMULA THAT I PUT A 383 MOTOR IN AND THE STOCK ECM NO LONGER RECIEVES ANY INFO FROM THE MOTOR. THE TORQUE CONVERTOR DOES NOT LOCK. THE 700R4 (ORIGINAL TRANNY) HAS A THREE WIRE CONNECTOR GOING TO THE DRIVERS SIDE OF TRANNY, LIGHT GREEN WIRE, LIGHT PURPLE AND TAN WITH BLACK STRIPE. DOES ANYONE KNOW HOW I CAN WIRE A MANUAL OR VACUUM SWITH TO THIS COONNECTOR TO LOCK THE CONVERTOR? OR DO I HAVE INSTALL SOME KIND OF PRESSURE SWITCH?

 

Yes you will need to install a vac pres switch and may need a different type in the VBody as well. All easily done and may require dropping the pan. What is the orig engine (vin code and ID)

 

THE ORIGINAL VIN IS 1G2FS21E1JL203428 - DOES THE PRESSURE SWITCH GO INTO THE TRANS CASE ON THE DRIVERS SIDE (SAW A PIPR THREAD PLUG THERE) AND WIRE INTO THE 3 WIRE CONNECTOR?
THANKS

 

No. Those are pressure testing ports. Leave those alone unless you are doing a test on the fluid pressures. The PressureSwitches for the TCC operation are on the ValveBody ends. Requires dropping the pan. That 4-pin and 3-wire connector is for its function. Usually there is 12V ignition, a Ground and a Signal OUT to the ECM there. 8th Digit is E which denotes your orig engine as 5.0 TBI if I am correct. I dont have a specific schematic for it on hand myself. I have a post on a thread with a diagram of HOW-TO wire it up inside and out of the tranny so you have Lockup in 4th gear. Ill try to find it and get back. Maybe it will help.

 

Heres that link to the post. Scroll down a bit. Youll see pictures and drawn on illustrations...cant miss it https://www.thirdgen.org/forums/tran...r-lock-up.html