1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

700r4 Painless Tcc Lockup Install

Discussion in 'Automatic Transmission' started by ljames86350, Jan 13, 2020.

  1. ljames86350

    ljames86350 Junior Member

    Likes Received:
    Jan 11, 2020
    First Name:
    Truck Year:
    Truck Model:
    Gmc k1500
    Engine Size:
    350 3970010
    New to the square body forum and I think I could use some help. I’ve got an 1986 gmc k1500 with a not so original small block 350 with a 700r4 trans. Truck used to have a 305 with cruise control and Ac. No more cruise and ac’s not hooked up. Converter burned up due to some faulty wiring going to the trans and the 3.08 gears with 35” tires didn’t help. All is rectified except wiring of the trans. I picked up a painless lockup kit that comes with all the wiring, vac switch, brake switch, 4th gear psi switch and tcc solenoid. That way I know the trans will be working when I’m done. Inside of the trans is wired up. I’m working on wiring up the brake switch currently which has 2 plugs to it. Ones for brake lights (orange and white wire plug) and the other plug (3 grey wires one has black stripe) was for sending power to the vac switch that led to the trans I believe? What I believe is the trans wiring, leads to a white box above the main fuse box by the steering column (wires turn green with 2 blues coming out the white box) before going through the firewall to the trans. Anyone know what that white box is? What it controls? The new brake switch just needs an ignition hot wire going to the rear plug that’s not the brake lights but if I unhook the old plug and hook up my wires what am I unhooking?? Instructions did mention running the existing brake switches and adding this new one to the pedal on certain models with cruise but I’m not using cruise. Was hoping not to have to fab up a mounting bracket and a 3rd switch. Not much room in there. Other thought was to remove the cruise control switch and let it hang and install the new brake switch in its bracket... thoughts? Sorry about the pics, haven’t ripped the dash apart yet, hoping not to have to.
    Painless instructions





Share This Page