200-4R wiring

Discussion in 'The "Juice Box"' started by S2X01, Jul 5, 2012.

  1. S2X01

    S2X01 Well-Known Member

    Okay...I've read a million things. Trying to simplify this and wire it up tomorrow.

    Here's the harness I have. Top left we'll call purple. below that is a brown/black wire, and the one on the right is blue.

    Now look at this diagram I found.

    Can I assume, that with a relay, my lock up will only engage when the toggle is on AND the trans is in 4th gear?
    This sound optimal to me. By that logic, any time i mash the throttle, and my trans kicks down, my lock up will disengage?
    I'm fine with no pressure switches or brake switches. I'll just turn things on when cruising or on the highway.

    Will this work? I'll assume my purple is the same as the red on the diagram. Yah?

    Thanks guys! Hopefully I'll be rolling this weekend!!
  2. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    So does the Blue wire ground out when it shifts into 4th? I have a 2004r I need to rebuild and will be in this scenario in the next year, but currently do not have the answer. A bit over ten years ago I had a 700r4 rebuilt for me by the trans guy at the dealership I worked at, and he set it up to only have one wire come out of the plug that needed 12v to lock the converter up in only 4th. I thought inside the pan he wired one of the wires (blue one?) to a pressure switch and wired the ground internally so it just needed the 12v feed. And I hooked it to a toggle switch and always left it on with no issues even the couple of times I did lock the wheels up at highway speeds, the engine never stalled. Of course that is a 700r4, so there can easily be differences between that an the 2004r.
  3. S2X01

    S2X01 Well-Known Member

    From what I know....a relay needs 2 power sources, and a ground.
    By this diagram, there is a constant 12V, a 4th gear 12V, and the switch completes the list.

    Seems simple enough..... I just can't find a diagram of the pins to find out if my wire harness is correct to the diagram!:Do No:
  4. GS Jim

    GS Jim Platinum Level Contributor

    The Pink wire goes to a 12v source and the Brown wire goes to a ground. I have a manual switch for Off and On for mine.
  5. S2X01

    S2X01 Well-Known Member

    Can anyone even tell me which pins are which?
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

  7. steve covington

    steve covington Well-Known Member

    Looking at plug with three wires, 'click' lock tab to your left
    pin A is top left, 12 volt positive from brake switch to TCC solenoid, red wire internal
    pin B is top right, ECM control, black wire internal
    pin C is bottom right, blank, not used, N/A internal
    pin D is bottom left, ECM ground for TCC solenoid, Blue wire internal

    | A B |
    < | |
    | D C |
    Sorry, that is the best I can make it .

    Basically, you need 12 volts coming from the brake switch when it is up to wire terminal A to power the TCC solenoid.
    A "controlling circuit" to activate the TCC solenoid on wire terminal D to ground and activate the TCC
    Another wire is used on wire terminal B to get input to various functions from the ECM, particular to the transmission. Some go to a 4th gear clutch switch, some go parallel to a 4th gear clutch switch and to a temperature switch to alternatively perform the gound circuit in addition to wire terminal D. Sometime the 4th gear switch is a normal open, sometimes it is a normal closed. Depends on the application. USUALLY it is a NORMAL OPEN switch...USUALLY...
    BIGGEST feature you need are inclided in terminals A and D, the two wires closet to the 'click' retainer. You would need the specific model trans, or taking the pan off to determine correct wiring usage for terminal C
  8. GS Jim

    GS Jim Platinum Level Contributor

    Well gee, what do I know. Six Years using a $2.98 switch from Radio Shack and no problems.
  9. S2X01

    S2X01 Well-Known Member

    Do you just kick your switch off when down shifting/stopping?
    The reason I like the relay, is that the 4th gear +12 will take some of the switching out(in theory)

    If there is in fact +12 coming from the blue when it's in 4th, that eliminates manually switching all the time.
    If I can't find any more info though...I may just run the simple toggle setup.
  10. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Won't it automatically disengage when you get to 2nd or 3rd gear when slowing down? I don't think there is valving to keep it locked in 1st or 2nd. :Do No: As I mentioned on my 700r4, I just left it on all the time however the internals were wired it was okay with that.
  11. S2X01

    S2X01 Well-Known Member

    Yeah...that's my thought with the relay. Once I start braking, or puch it and it kicks down, it comes out of 4th, no more secondary power to the relay, and the clutch disengages.

    Provided my pins are right though.
    Mine look a little different than what Steve posted, just because my "lock" is at the top.
    But regarless, both on my trans and the harness, pin C...bottom left...is blank
  12. GS Jim

    GS Jim Platinum Level Contributor

    When coming to a stop the Gov knocks it down according to speed. It unlocks when you let off the gas. I leave it on all the time. I put it in there cuz I was running a 300 that was all ported out and it didn't like the lower power band being locked up. So I shut it off when running slow. Now that I'm running a 350 the torque is enough to pull it when locked at lower rev's. So no problem.
  13. afracer

    afracer Well-Known Member

    I just bought a TCI converter lockup kit for like $80, vaccuum or switch operated so I can lockup the converter in any gear if I want to...
  14. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    The two most common mistakes with the 2004R wiring are this:

    1. Many people add the switch to the power wire instead of the ground. Keep the power to the trans at all times and control the lockup with the ground via a switch.
    2. Many people do not add a brake switch. Any vehicle with a lockup converter without a brake switch to shut off the lockup is a death trap. If there is no brake switch then the vehicle can stall under an emergency braking event. Been there done that with a fuel injected truck, almost killed myself because the truck stalled and I lost power brakes, power steering, ect at 80 MPH.
  15. GS Jim

    GS Jim Platinum Level Contributor

    I've heard of people wanting to lock up 2nd and 3rd gears. Why would you want to do that. You would lose the benifit of the T/C. Why not just install a 4 Speed manual.
    When I punch it, it unlocks and drops down accordingly, 3rd or 2nd. When I get back to a steady speed it hits 4th and locks up about a second later.
    This is going from memory. I haven't driven it in well over a Month.

  16. steve covington

    steve covington Well-Known Member

    The idea of locking up the torque converter in second and third was more with the TURBO BUICKS; it acted more like a manual transmission (with less slip) after getting off the line in low gear. Can't really say that it worked so well; I ended up having to have the transmission rebuilt shortly after doing that trick at the track a few times. Granted, ithe transmission WAS still in stock form and the engine had bigger injectors, bigger turbo, chip, air intake, and free exhaust; but the trans did fail after using the lock-up switch trick. Did it pick up any significant ET or MPH? Don't really know...I had done some mods from earlier track runs,,, on a different track,,,with different weather conditions...SO....who knows
  17. GS Jim

    GS Jim Platinum Level Contributor

    When I went to the Trans Plant at Buick for a sheet metal install I saw the 350 lock-up converters. All there was on the plate was a small round section of friction material. It was about 8" in dia and thin as a thick piece of paper. One Inch or so wide. I thought oh yea, that'll hold up well. That's back when the customers complained about a "Judder" at lock-up. I don't know what they did to fix it, probably not much. But if the 200-4R trans is like that the friction material isn't going to hold up long being locked up and bang shifted into each gear. I dont know if it's been improved or not. It sure is a lot thinner than a manual trans clutch. Works about the same tho.
  18. steve covington

    steve covington Well-Known Member

    Early lock-up transmissions used hydraulic actuation... which by the nature of itself was problematic. The trans would go into third gear, hydraulic signal was high enough to actuate lockup...with a mild 'shudder' This dropped the RPM which lowered the hydraulic signal which disengaged the lockup, and the cycle would repeat. VERY disturbing at nominal city street speeds; it would go away at typical highway cruising speeds (back when 55 was the limit).
    And yes, the lokup clutch inside most STOCK converters was only a single thin disc, not even as thick as a piece of corrugated cardboard. They were meant for actuation only under relatively stable speeds, where the load was not that high. It doesn't take a lot of power or torque for steady state speeds...
    Early (81, 82) 200-4r also had this hydraulic lockup feature. Those cases are only good for scrap aluminum for value... If the case does NOT have a 4 wire CAPABLE plug on the side (most only used three wires out of the four holes), it aint worth having.
  19. Loyd

    Loyd Turbocharger junkie

    The logic of the diagram will work, assuming all 200 4R have open switches in the respective gears. I do not know if the connections are on the right locations on the connector. There are too many variations of how the TCC is hooked up, between various 200 4Rs. I would advise pulling the pan and confirming which pins go the 3rd and 4th gear switches and which two go to the the solenoid.

    Here are the variations between the 200 4R for the VIN Y application and the 200 4R for the VIN 7 Buick applications:



    If you give us the code off the tag for the transmission you are using that would be helpful. Buicks are BRF for the Turbo Regal and BF for standard Buicks.

    When the pan is down make sure that only the 4th gear switch grounds terminal B. The 200 4R for a Vin A Buick both the 3rd and 4th gear switches would ground terminal B and close your relay.

    Your plan is sound. I would not worry about breaking the power to Terminal A with brake switch actuation, but it is a safety measure you could add down the road. I pulled a brake light switch with an extra normally closed connector at a pick and pull out of an 80s Caprice.

    Last edited: Jul 12, 2012
  20. GS Jim

    GS Jim Platinum Level Contributor

    Loyd, If I took the pan off my tranny I'd be even More confused. Not to mention having an oily face. :laugh: I'm lucky, I found an '87 BRF in a yard still in the car. Fast ratio steering box too. 235 total. Couldn't get my plastic out fast enough.

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