mj9311

so i have the 700 r4 and to wire the lock up i need a brake switch but there are 3 wires in the plug so i dropped the pan to check it out







so the black (im going to assume is the ground) runs from the plug all the way back to the solenoid?? (blk-) it says

one brown wire runs to the green caps
and the other brown wire runs from the plug to one of the yellow caps and then from the other cap back to the solenoid (red +) it says

any suggestions of how this should be wired up?? any help is appreciated

markdtn

Can't help you inside the pan, but there are kits available from Painless or Howell or Street and Performance. Basically most hook the 4th gear pressure switch to the lockup ground and have 12v supplied externally. This makes it so that if you are in 4th gear and apply 12V it will lock the converter. You couple that with a brake switch and you have a system. Mine also has a vacuum switch so it breaks the lockup circuit when there is no vacuum. Hope this helps.

TimAT

I don't trust my memory 100%, but the switch with the single wire is the 4th gear switch and the 2 wire is the 3-4 pulse switch. Pulse senses the shift and unlocks the TCC when the 4th switch sees enough pressure to lock. IIRC the idea was to slow down the 4th TCC lock a little so you didn't feel a "shift bump" as GM called it.

Pull the 4th gear switch out and hook it to a regulated air supply- slowly apply pressure with it hooke to a multimeter (ohms scale) and see where it closes. IF it closes about 40 psi, use that to ground the TCC solenoid and forget the other one.

It's been a long time, so double check!

mj9311

thanks for the input all i need to know is how to wire it from the plug out i know it needs a 12v feed and a brake switch but i am still uncertain what wires go to what

TimAT

Use the black wire as it is- it's going to the switch, so when is sees pressure it goes to ground. Use the white wire from the solenoid as the +12v feed.

I'd still hook that switch to an air source and see where it closes. It really needs to be at 40PSI or a little over so you don't get a shudder if it comes on to early. It seems to work out the 4th gear pressure that switch sees is close enough to 1:1 with road speed- 40PSI=40 MPH

mj9311

so im a little confused on the air test... does this mean im going to also need vacuum to the trans or is that just an alt test??

TimAT

Take the switch out, hook it to a regulated air supply and use a meter to see what the pressure is when it closes. Noting complicated.