Where do I find the info on how to install a switch and hotwire the system to manually use the converter lock up on my 1981 Vette.
CCC has been removed. Thanks.

CCC... neat idea... bad implementation.

It should be rather straight forward. I can't believe there are more than a few wires going into that transmission.

If nothing else, the Helm Factory Service Manual should have what you need.

I will warn you, though, the FSM from those days might be a bit of a kluge. Gordon Killebrew himself said that they started with the FSM from 1968 and just added crap to it. Sometime in about 1980 or 81, they actually re-wrote it to better integrate the additional electronics. I THINK 1981 is ok.

I wish I knew the wiring schematics...

You would need to cut the tan/black stripe wire going to the "D" terminal of the trans connector. Then put your switch in this circuit. This is the ground side of the circuit, which is controlled by the ECM. You would need to ground the side of the switch going away from the trans, or, in other words, on the ECM side. Chances are, your "Check Eng" light is going to shine if you command LU on when the ECM thinks it shouldn't be on, but it should be fine if you dis-able the LU until a later time/speed.
Inside the trans is a pressure switch, and depending on the rating of the switch, the trans may or may not have LU until the switch closes, regardless of your on/off switch position. The pressure switches come in many different ratings, corresponding to vehicle/governor speed. Most factory switches are rated somewhere around 38psi/mph, meaning the switch will close at 38mph, allowing LU to function. Changing the pressure switch to a higher PSI rating will raise the speed at which lock-up occurs. I prefer a 58psi switch for most applications, but, with fuel prices the way they are now, a lower rating might be good...
hth

(I'm attempting to load a graphic that shows a basic 350 LU circuit...hope it works.)

Attach file:

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  350C.JPG (20.88 KB)

Many thanks - will do the work pretty soon.

Why not just use a vacuum switch? It seems like you'd be hitting that switch back and forth all the live long day.

With it on, you may find the converter locking up unexpectedly as soon as you hit that speed (depending on your pressure switch), and making the car lug and sputter bigtime.

I used p/n GM 14014519 for the vacuum switch, and 12101914 for the connector. If you wire this inline with your brake cancel switch, and run it to a ported vacuum source, it will unlock the converter under heavy throttle, and also during coasting.

Otherwise, you pretty much always want the TCC locked up in 4th (or 3rd for a th350). But that part is done within the transmission, and I don't know exactly what pressure switches and wiring setup is needed for that.