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Discussion Starter #1
I have two th400 transmissions and they each have a different electrical connection/switch at the rear part of the trannies. One has a single terminal and the other has two terminals, on the dual terminal switch one terminal is vertical and the other is horizontal. I did a search and found a thread that said they were for the kick down/passing gear.
How do each of these work and what do you hook up to the connection.
Does the single terminal one just need power run to it. If so, straight 12 volts? Can you split off from the lead running power to the distributor and run that power to the single terminal trans switch?
Dual terminal ?????
 

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its been a while

its been about 30 years ago ,, but i had a friend with one of those , he rigged a button on the shifter , can't remember if it was single or dual post. The single post prolly just needs power ran to it , and gets a ground through the housing on the switch. Get an ohm meter and read the resistance from the post on the switch to the transmission case. Umm ,, prolly should be less that 50 ohms or so but not a direct circuit with 0 ohms. The dual terminal will prolly need both power coming from a switch and ground going to the chassis to work

I think i'd look around for another power source than the ignition myself
 

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Discussion Starter #3
When you say your friend used a button. Do you me he pressed the button when he wanted to down shift?
I am trying to hook it up so the trans down shifts when it needs to on its own.
If you you just run a power lead to the single terminal will it operate on its own, the way it is suppuse to.
If there is anyone out there that has a th400 in there car, do you just have a power lead to the terminal?

Thanks for the info.
 

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The vacuum switch can be over reacting.

Use a B&M 20297

The easy way to control your TH400.
These B&M kick-down switch kits are perfect for use when swapping out a TH350 or TH700R4 for a TH400. These kits mount to the factory throttle cable bracket for easy kickdown control.

http://www.jegs.com/i/B&M/130/20297/10002/-1?CT=999
 

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Is it possible he has one of the "Switch Pitch" equiped TH400's? Some of the big block Camaro's came from the factory with this feature. 12 volts applied changed the pump presure feeding the convertor causing it to raise the stall speed. Higher stall speed at the flip of a switch. It did'nt work all that great. I think it raised the factory stall speed on a TH400 form 1200 to 1600 RPM. I can't remember if there was a sperate electrical connection or not. John Kilgore used to build lots of these Th400's for hot rodders in Los Angeles back in the late 70's, early 80's.
Ron
 

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Discussion Starter #8
That book is just what I was looking for. Thank you.

I too have had th400 in various cars over the years and did not hook anythng to the terminal.
I just purchased a 1972 C-10 for my sons birthday (He likes trucks better than cars:eek:) I accused my wife of spending time with the milkman:rolleyes:!!! LOL.
The truck is a pro street custom and the motor in it had more Horsepower than I wanted him to have for his first vehicle. We pulled it last weekend and it had a th400 behind it with a power lead running to it spliced off of the power lead to the distributor. I have a couple of stock sbc's so we bolted on some hop up items included a few items for some BLING!!!!! and we will put it back in the truck next weekend. Would have put it back in this weekend but this was his high school prom weekend. Things have changed since I was in high school, I was at the drag strip "slammin" gears during my prom weekend:D.
Back to the subject, I had never seen power run to this before so I thought I would ask and see if anyone knew what this did. I purchased the truck from the previous owners widow so I could not ask him and the trans does not look to be a specialty one. Thanks you,
 
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