th 400 87 chevy truck not shifting

I have recently swapped out my tbi for edelbrock multi-port fuel injection on my 454 1 ton chevy.  I removed my factory ecm computer to install edelbrocks computer.  Well I have a th400 that wont shift automatically because that little orange wire that comes off of the tranny is just hangin there.  I couldnt find a kickdown switch at all on my throttle on the tbi or on the gas pedal in the cab.  I know theres a transmission relay on the firewall.  According to mitchells wiring diagrams the little orange wire goes to the transmission relay then to the computer I no longer have.  Is that correct and if so what can I possble do to get transmission to shift.  Any help would be great because Im totally stumped.