Your transmission is most likely a 4T60E. If so, it has no modulator valve. This transmission is electronically controlled from the ECM. Line pressure, which is what the old modulator valve controlled, is now controlled by an internal pcm solenoid.
The horn on a 1996 Chevy Corsica is located just behind the driver's side headlight in the engine compartment. There is also a horn relay switch in the lower part of the dash just to the left of the steering wheel.
Remove the wiring harness from the back of your 1996 Chevy Corsica blower motor. Remove the blower motor retaining bolts. Remove the fan from the front of the blower motor. Reverse the process to install the new blower motor.
NO. NOT EVEN CLOSE. Chevy redesigned the engines and transmissions in late 1999. If you need a transmission for the 96 truck Then the only 1 you can use is a 1996 4L60E transmission. If it wasn't a 1996 model then finding 1 would be NO problem.