2nd Gen Non-Engine/Transmission Manual Lock Up Switch, with relays

[sag2]

I installed this lock up switch today and it works great. It is much better than just a switch as it locks up with the switch, but cancels with the brake input, and lets the PCM take over if it meets the normal criteria for lockup. I used mini relays, but it would work with any ISO relays. I would also like to add a pressure switch in the governor port that would prevent an accidental lock up when stopped, or kill the lockup below the pressure set of the switch. I added the LED so I would know when the TC is manually locked. When the PCM takes over, the LED goes out.

 

[sag2]

OK, I'll explain the operation for some clarity.
Looking on the diagram the relays are numbered from left to right, 2 (Torque converter), 4 (PCM), 1 (Latching), and 3 (Brake).

When you want to lock up the converter you press the push button. That latches relay 1, and also powers relay 2. Relay 2 now grounds the torque converter solenoid in the transmission. The converter is now locked up. The LED also lights and stays lit. If you step on the brake, relay 3 turns on, and pulls the power from the ignition feed. If you are locked up, say in fourth gear at 35 mph and you accelerate to 50 mph, as the PCM grounds the circuit to relay 4, relay 4 then pulls the ground path to relay 1 and the PCM is now in control of the converter. The LED also turns off.

 

[JJPage]

Thanks sag2, already have my circuits connected, but your's provides a safeguard! Would not be that difficult to incorporate the relays into my circuit.