1227747 and 700r4 TCC wiring

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11-09-2013
damanx

1227747 and 700r4 TCC wiring

Need to wire up the TCC to the ECM.

Being that the truck was previously carbureted, it used the brake switch and a vacuum switch to lock up the TCC.

I'm not sure how the solenoid actually works so I don't want to assume anything, but here's what I have:

Two wires going into the connector on the tranny.

One is blue. As long as the ignition is on, there is 12vdc on that until the brake pedal is pressed. This seems to match up to the drawings.

The second is green. It comes from a vacuum switch that is operated by ported vacuum. When the vacuum reaches greater than 10", the switch closes and 12vdc is fed to the other pin of the connector going into the tranny.

Now, I am thinking I need to run A7 to a relay to provide a ground to the relay to turn it on, then feeding 12vdc to the green wire.

Make sense?
11-09-2013
Dewayne_S

The way I have my 89 Camaro wired (was a 5 speed) one wire to the ecm and the other to the brake switch to supply 12v.
11-10-2013
damanx

Looks like it's supplying 12vdc either via the brake circuit of via the vacuum, which either of each will unlock the TCC depending on the condition.
11-10-2013
EagleMark

Right, power always on through brake switch to TCC solinoid and a wire to ECM that is ground for lock up. If brake is applied? Looses power.

http://www.gearhead-efi.com/Fuel-Inj...7&d=1331599707
11-10-2013
damanx

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.

http://i761.photobucket.com/albums/x...psc078b9df.jpg
11-10-2013
Fast355

Quote:

Originally Posted by damanx

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.

http://i761.photobucket.com/albums/x...psc078b9df.jpg

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.