41 Buick Coupe with 455 and 400 tranny need assistance

I have a question regarding the1975 buick 400 transmission. On the drivers side, there was a plug with I believe a brown colored wire. I was told that it was for the neutral safety switch. Upon further research, I'm begining to think that maybe it was power for the kick down feature since this trans doesn't have a kick down rod from the carburetor. Any comments on this particular wire would be appreciated. Also, how does the kick down work in this type of transmission. Your comments will be appreciated.

 

Kickdown is electric, that wire gets 12v when you push the gas pedal down all the way. Inside the trans, there's a solenoid that opens and lets a valve move, etc.

You need to add a switch and some wiring if you want it to kick down, KD is fun with a big engine

 

The switch for the kick down is on the throttle linkage somewhere,some are in the engine compartment and the later versions might be on the gas pedal. Its been over 15 years since I had a vehicle with a TH400 so my memory is a little fuzzy,grampa had a 66 Olds and I think it was on the linkage behind the carb and my 72 Olds 98 was up under the dash.

 

That is the connection for the transmission kickdown. If I rember right Buick used a switch on the intake manifold that the carb linkage activated, all the rest of the GM brands used a switch that was activated by the throttle pedal. On my 39 coupe with a Pontiac engine I used a Buick switch on the intake manifold, and my convertible I used a micro switch mounted near the throttle pedal that the pedal activates

 

https://www.google.com/search?q=tur...rAGKO92wWQ2YGQDg&ved=0CEkQ7Ak&biw=320&bih=504

I've seen factory setups that have manifold mounted switches in plunger, rotary, and micro limit style that work off the throttle arm or linkage. I've seen under dash mounted switches that work off the gas pedal, I've seen aftermarket setups that get the job done by usually a pull switch, and I've seen owner installed manual switches.

 

Lokar makes one that mounts to carb base. Do search on Ebay too.Be sure modulator has a direct manifold vacuum source

 

Nitrous micro switch also has mounting supplies to go on side of carb .

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Thanks to all that responded. I will start looking on the carb/manifold to see if I can find the solenoid that sets it off.

 

There would be a switch on the carb, not a solenoid. The solenoid is in the transmission.

 

Thanks Jim. My incorrect use of solenoid. I had a feeling I was using the wrong terminology. In any case, thank you very much for the assistance. I hope I can get it right.