1227747 and 700r4 TCC wiring

[Fast355]

The TCC ground signal from the ECM will have to feed a relay that will provide 12vdc to the TCC solenoid.

Took me little bit to figure it out because the '84 and '85 s/t service manuals do not show the wiring for the TCC vacuum switch.

This is the diagram for what I need.

Looks like it was wire alot like my 83 G20. Except both blue and green wires run into the firewall connector and both run into the trans as well. On my 83 G20 the vacuum switch controlled the TCC in 2nd and 3rd gear in 4th gear lockup was controlled by a pressure switch in the valvebody and brakeswitch alone. The wiring also controlled the EGR bleed solenoid that bleed away the vacuum signal to the EGR valve in 4th gear and allowed additional air into the engine via a metered air leak.