I found the TH400 kickdown harness, now what?

Discussion in 'Sparky's corner' started by Tim, Jul 27, 2004.

  1. Tim

    Tim Silver Level contributor

    I have a 72 Skylark 350, TH350 that I am putting a TH400 S/P into, I bought the correct gas pedal, bracket and kick down switch for the TH400. I was going to wire it to a 12 volt source but I just found the factory kickdown wire connector tucked up under the dash.
    I would like to be able to plug this onto the kickdown switch and use it. My TH350 trans had a pink wire running to it that was connected on the side of the tranny like the TH400 but with only one solenoid connection.
    I plan on connection my high stall to a headlight dimmer switch on the floor.
    Can I use the factory connection for the kickdown, if so can I use the pink wire from my TH350 to the TH400 for the kickdown function and then just run another wire for my high stall??
    What are my options?
    Thanks
    Tim
     
  2. 462CID

    462CID Buick newbie since '89

    ...your TH350 had an electrical solenoid kickdown?
    It is my understanding that any TH350 for a Buick, 70-72 uses a seperate kickdown cable on the gas pedal, while only the TH400 used a solenoid.

    Can anyone clarify or expand on that?
     
  3. Tim

    Tim Silver Level contributor

    No it is not a kickdown, but it does have a wire hooked up to it, the connector on the TH350 looks the same as for the TH400! I have the cable that is for the kickdown so I am not sure what the wire is for!!!
    Tim
     
  4. TimR

    TimR Nutcase at large

    That wire is for the TCS system. Basically there is a switch on the side of the tranny (RH on the TH350 and LH on the TH400, which also has the kickdown connector located there too) which sense line pressure.

    The idea is that there is no vacuum advance in 1st and 2nd gear, and then 3rd gear gives full advance, this to meet the federal emission standards. There is a small vacuum solenoid, electrically operated, connected into the distributer advance system. It is usually mounted on the carb...when the tranny is in 1st or 2nd gear the solenoid is operated and bleeds off vaccum to the distributer. In 3rd gear it closes and the distributer gets full vacuum for best mileage.

    You can't use this for a kickdown switch on a TH 400.

    Its easy to add to your harness though. The connection is already there on the passengers side of the firewall, you need to pop off the engine compartment side engine harness connector, then add a connector and wire down to the detent connection on the 400.

    You'll need a wiring diagram to locate the correct position in the connector.

    later
    Tim
     
  5. gstewart

    gstewart Well-Known Member

    timr:
    i would surmise that the tcs usage would not apply to the 72's
    that were for export only to canada . my 72 is out of fremont , no air pump , nor tcs .
     
  6. TimR

    TimR Nutcase at large

    Wierd! Every 72 455 car I have here or have seen has the system or remainders of it (first stuff to get yanked usually). My 71 had it as well....I have yet to see an AIR pump though.

    Later
    Tim
     
  7. gstewart

    gstewart Well-Known Member

    timr:
    he is talking 350 ci . i donot know about the 455 ci . perhaps i should qualify my earlier response to read "350 ci" and "no a/c" .
     
  8. TimR

    TimR Nutcase at large

    Hi Gerry, perhaps I should have explained myself better...(isn't this stuff great??:grin: )

    Anyway. my 72 GS 350 ragtop, flint car, has the TCS system on it (I just spent an hour digging out the complete engine/tranny from under a bunch of stuff..it makes a great bench!!). This car has original engine but tranny was replaced. I unpeeled the engine harness enough to see the wires better, one side of the TCS solenoid on the carb has a pink power wire that runs back to main power, the other wire coming off of it is pink with a black stripe and runs back then comes out of the harness in the exact same spot as the heater blower motor does (ie, back of the engine, rh side) Mine was tie wrapped up in a circle to the tranny down near the rh side of the pan and the end was cut off (not torn, but cut cleanly cut most likely when tranny was replaced with later model).

    This matches all my assembly manual pictures and diagrams.

    Anyway, it really doesn't matter. What matters is that the wire cannot be used to run the kickdown for the TH400 going in.

    You need to pop of the engine harness connector (engine side of firewall) and plug in a new wire so it connects with the already existing setup for the TH400 kickdown.

    Take off the bolt, and on the diagram it is #12 when looking at the terminals sticking through the connector. You will need to add a terminal and wire to the blank spot you will have there.

    Everything gets so confusing!

    later
    Tim
     
  9. Tim

    Tim Silver Level contributor

    Ok, thanks, I am running a switchpitch and I have wired a dimmer switch to the high speed and just ran a new wire from my kick down switch to the tranny!
    Tim
     

Share This Page