700r4 TCC not unlocking when braking

[johnathan]

My torque converter does not unlock as I decelerate. It unlocks with a loud clunk just before coming to a stop. I've read that the TCC is wired through the brake light switch and the ECM. Where is the ECM located?
Also, is there anyway to keep it from locking in third. It will lock up even with a 1/2 pedal,that can't be good for the clutch with that much load on it.

 

[dyeager535]

If we are dealing with your 1984, then no, it does not go through the ECM. There is a brake and a pressure switch. Brake switch is what unlocks the converter when on the brake. Brake switch is above the brake pedal, there might be one or two switches above the pedal...you'll see the plunger on them move as you move the pedal. Cruise, TCC, and the brake lights all operate off of those switches, TCC may or may not be integrated into one of the two switches.

You adjust them to where they need to be by wiggling them in or out...if they move easily, they probably need replaced, as the plastic ribs on them eventually wears down and they won't stay in place.

I've never seen more than two brake switches, one with two sets of wires running to it, one with one set of wires running to it.

 

[johnathan]

Yes its the 84,sorry. Yes there are two switches.The brake light switch has three wires to the back,as the two coming in the side control the brake lights. The other switch, I'm guessing is for the cruise,has power to the wires and a large vaccum hose which has been plugged. They seem to be tight in place.

 

[dyeager535]

Yep, vac hose one is the cruise switch. Sounds like the brake one is also the TCC switch. You should be able to use a continuity checker to see that the switch is still operating correctly on the back.

I would assume that key on, brake not applied, there should be continuity across the two terminals, but that's a guess.