TH-400 Kickdown cable...
Thread Starter
Drifting
Joined: Sep 2010
Posts: 1,581
Likes: 50
From: Prosper TX
TH-400 Kickdown cable...
I want my car to downshift when needed versus having to manually downshift the car. My car doesn't have (missing) the kickdown cable on the TH-400 to the Edelbrock carb.
I can't for the life of me find the right cable for this application, as there seems to be so many choices and I don't want to buy the wrong one.
Can someone help me find the right cable and all that I will need? Is it difficult to install? Any photos and/or step-by-step would be very helpful!
Thanks!
I can't for the life of me find the right cable for this application, as there seems to be so many choices and I don't want to buy the wrong one.
Can someone help me find the right cable and all that I will need? Is it difficult to install? Any photos and/or step-by-step would be very helpful!
Thanks!
Thread Starter
Drifting
Joined: Sep 2010
Posts: 1,581
Likes: 50
From: Prosper TX
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
The switch is mounted to the upper part of the bracket under the dash the gas pedal is mounted to. Pretty simple on-off type thing, just a pin sticking out that the arm on the pedal pushes. Check to see if it's getting power, then check the other side (key on, engine off) to see if the other wire gets power when the switch closes. After that, check at the trans- single wire connector on the left side, close to the shift lever. (maybe check and make sure it's plugged in/connected first). If it's getting power to that connector, then the problem is inside the trans- easy fix- drop the pan, replace the solenoid, you needed to change the trans fluid/filter anyway, right?
Thread Starter
Drifting
Joined: Sep 2010
Posts: 1,581
Likes: 50
From: Prosper TX
Well the good news was I was able to locate the switch...so it's there. Not easy to see...I never knew my body could twist into positions like that before....
I was pretty excited at this point that I might have automatic kickdown coming tonight. However, I turned on the key without starting the engine and move the pin multiple times to see if I could hear anything click. Nothing. No sounds anywhere.
So now I need to track down two things. I need to see if I have power at the switch, and if I do, then most likely will need to replace the solenoid in the transmission.
The question is...how do you test at the switch to see if it's good/bad? I mean I can't see any possible way of getting any tool or measuring device in that tight space. Any recommendations on what you would do next to solve for this problem?
I was pretty excited at this point that I might have automatic kickdown coming tonight. However, I turned on the key without starting the engine and move the pin multiple times to see if I could hear anything click. Nothing. No sounds anywhere.
So now I need to track down two things. I need to see if I have power at the switch, and if I do, then most likely will need to replace the solenoid in the transmission.
The question is...how do you test at the switch to see if it's good/bad? I mean I can't see any possible way of getting any tool or measuring device in that tight space. Any recommendations on what you would do next to solve for this problem?
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Pull the wire off of the solenoid on the driver side of the tranny, put a test light in it and ground the other side of the test light....have someone put the pedal on the floor and watch for the test light to light up.... if it DOES light up, that means the wiring/switch is good and the solenoid is bad or bad connection.... If it DOESNT light up, then either the switch is bad(this is common) or you have no power to the switch and you will have to chase the power back from the switch up to the harness.
If its all working, you will hear the solenoid clicking inside the pan very lightly...
My guess is your switch is bad...they wear out right in the area of its travel where WOT occurs... You can get them new from GROUND UP parts...its a chevelle website but they use the same switch...only place I have found them new.
If its all working, you will hear the solenoid clicking inside the pan very lightly...
My guess is your switch is bad...they wear out right in the area of its travel where WOT occurs... You can get them new from GROUND UP parts...its a chevelle website but they use the same switch...only place I have found them new.
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Thread Starter
Drifting
Joined: Sep 2010
Posts: 1,581
Likes: 50
From: Prosper TX
Than you Al! That is exactly what I'll do. I'll let you know the outcome.
Now if only I was 4 inches shorter and 50 pounds lighter to get down there and do this. Wait....I have kids
Now if only I was 4 inches shorter and 50 pounds lighter to get down there and do this. Wait....I have kids
Burning Brakes
Joined: Jun 2008
Posts: 1,086
Likes: 1
From: Michigan
The switch at the top of the accelerator rod is self adjusting. If it gets out of adjustment it will appear to be defective but it may not be.
With your thumb, push the cream colored tab shown in redvetracr's pic up and toward the engine. Push hard. When you hear a click the switch is in a position to automatically reset itself. The next time you go to WOT the switch will reset itself.
After the switch resets do what others have suggested.
That switch also energizes the solenoid for the cowl induction in the hood. You may fix that as well by resetting the switch. If you can hear the cowl induction door snapping open with the pedal at WOT and the key in the "on" position than the switch is working correctly.
With your thumb, push the cream colored tab shown in redvetracr's pic up and toward the engine. Push hard. When you hear a click the switch is in a position to automatically reset itself. The next time you go to WOT the switch will reset itself.
After the switch resets do what others have suggested.
That switch also energizes the solenoid for the cowl induction in the hood. You may fix that as well by resetting the switch. If you can hear the cowl induction door snapping open with the pedal at WOT and the key in the "on" position than the switch is working correctly.
Last edited by 08vycpe; Jul 15, 2011 at 11:18 AM.
Burning Brakes
Joined: Nov 2006
Posts: 893
Likes: 7
From: Orange Park Florida
Also, check the gas pedal "travel". After years of use, the pedal shaft/lever gets bent and may have to be adjusted for full contact to the kickdown switch. To adjust, simply reach down to the gas pedal, grab hold of the pedal shaft and pull towards you - it will bend, Then check to see that at full pedal the kickdown switch is operated.
Thread Starter
Drifting
Joined: Sep 2010
Posts: 1,581
Likes: 50
From: Prosper TX
Also, check the gas pedal "travel". After years of use, the pedal shaft/lever gets bent and may have to be adjusted for full contact to the kickdown switch. To adjust, simply reach down to the gas pedal, grab hold of the pedal shaft and pull towards you - it will bend, Then check to see that at full pedal the kickdown switch is operated.
Burning Brakes
Joined: Jun 2008
Posts: 1,086
Likes: 1
From: Michigan
You're right. It wasn't making contact so I went ahead and bent the pedal up. I have more to bend as it doesn't move the switch all the way forward, but maybe 30% or so. However, I was able to move the switch by hand and didn't hear the click. Off to troubleshoot with the light now!
Thread Starter
Drifting
Joined: Sep 2010
Posts: 1,581
Likes: 50
From: Prosper TX
I never heard the solenoid at the transmission, therefore I am trying to determine power at the switch first. Maybe I'm wrong, but I don't think the self adjustment will make the 'click' from the solenoid start working?
