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  #1  
Old 04-14-2021, 08:06 PM
CDL CDL is offline
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Test/Troubleshoot Kickdown Switch

Part #001 545 63 14. 2 prong. Under the gas pedal type. Seems to operate as a spring backed button toggle.

Nothing ever happens because of it. My guess is it should toggle from open circuit to closed circuit with each single snap.

This one is always open circuit no matter how many snaps.

Q1) Is my assumption true?

Q2) Is this one dead?

Q3) A new one should be testable in my hand with a meter for open and then closed, right?

Thank you.

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  #2  
Old 04-14-2021, 08:25 PM
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Yes to all 3
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  #3  
Old 04-14-2021, 08:47 PM
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Thank you. ....going back to buy another 'new' one ...
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  #4  
Old 04-14-2021, 09:22 PM
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Quote:
Originally Posted by CDL View Post
Part #001 545 63 14. 2 prong. Under the gas pedal type. Seems to operate as a spring backed button toggle.

Nothing ever happens because of it. My guess is it should toggle from open circuit to closed circuit with each single snap.
This one is always open circuit no matter how many snaps.

The KD switch is not a toggle.
It is normally open, and closed only when firmly pushed.
The spring returns it to the NO state.
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  #5  
Old 04-15-2021, 10:09 PM
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Originally Posted by Frank Reiner View Post
The KD switch is not a toggle.
It is normally open, and closed only when firmly pushed.
The spring returns it to the NO state.
Thank you frank, but that doesn't seem correct. My experience has been that once engaged the trans stays in the lowest gear possible for RPM/speed and returns to normal once clicked again. 'race mode' . Perhaps there is something amiss with my switch?
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  #6  
Old 04-15-2021, 10:17 PM
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Originally Posted by CDL View Post
Thank you frank, but that doesn't seem correct. My experience has been that once engaged the trans stays in the lowest gear possible for RPM/speed and returns to normal once clicked again. 'race mode' . Perhaps there is something amiss with my switch?
The way Frank described the switch working is exactly how it works. Open at all times other than when fully depressed. It is a "momentary" contact switch.

The transmission is mechanical, the kickdown switch merely operates a solenoid valve to force a gear downshift. If you're hanging up in gears, you have a misadjusted bowden cable, modulator problems, or mechanical problems in the transmission itself.
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  #7  
Old 04-15-2021, 10:30 PM
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Interesting. The way it was working seems to make sense. You get compression braking as needed, no hunting around for gears and unwanted hard shifting up and down, always in the power range .... and when you are finished with the fun click it off, toggle style. Were there more than one type switches?
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Old 04-15-2021, 10:38 PM
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You have other problems if you're getting compression braking on one of these gearboxes. Nor should you be having hard shifting up or down. These gearboxes are firm, but they're certainly not harsh.
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  #9  
Old 04-15-2021, 10:54 PM
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Originally Posted by Diseasel300 View Post
You have other problems if you're getting compression braking on one of these gearboxes. Nor should you be having hard shifting up or down. These gearboxes are firm, but they're certainly not harsh.

Down shift and tell me you do not get compression braking? I didn't say Jake braking If the switch functioned as Frank said. and you were driving for max, it would be shifting up and down wildly each time you touched/engaged the kickdown or got off full throttle. . Think 'shifting a manual through curves'.



The way mine had worked that was NOT an issue. Think about it.



My switch died (cracked) and now looking for a replacement it seems the NA market does not meet the spec of the non NA vehicles. There must be more than one type switch available. Just like FPR's
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  #10  
Old 04-15-2021, 11:05 PM
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Don't we all?

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Originally Posted by Diseasel300 View Post
You have other problems if you're getting compression braking on one of these gearboxes. Nor should you be having hard shifting up or down. These gearboxes are firm, but they're certainly not harsh.

I do concede that I may have other problems, just not about this vehicle
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  #11  
Old 04-15-2021, 11:23 PM
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Originally Posted by CDL View Post
Down shift and tell me you do not get compression braking? I didn't say Jake braking If the switch functioned as Frank said. and you were driving for max, it would be shifting up and down wildly each time you touched/engaged the kickdown or got off full throttle. . Think 'shifting a manual through curves'.



The way mine had worked that was NOT an issue. Think about it.



My switch died (cracked) and now looking for a replacement it seems the NA market does not meet the spec of the non NA vehicles. There must be more than one type switch available. Just like FPR's
Not sure if you're a troll or just very confused with how automatic transmissions work.

Full throttle does not automatically press the kickdown switch, the kickdown switch is just that little bit further past full throttle, requiring you to push the pedal hard enough to activate it. The switch is very stiff and gives a very tactile "click" when you do.

So long as the kickdown switch is held down, you will remain in "passing gear" until the road speed reaches such a point that the valve body overrides the kickdown and shifts up. When you let off the kickdown switch, you should shift back up at least 1 gear (assuming you dropped 2), and should immediately shift all the way back up into 4th when you let off the throttle.

If you have behavior at all different than that, you have other mechanical problems that need addressing. There is no car (by any manufacturer) that requires you to hit the kickdown switch a 2nd time to cancel a kickdown command.

Regarding the MB kickdown switches, there are 2 varieties. 2 pin, and 4 pin. They're used globally, there is no different version for the NA market and ECE market. The 4-pin is typically used on later cars with the CIS-E injection system.
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  #12  
Old 04-16-2021, 08:02 PM
CDL CDL is offline
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All I know is how mine has functioned for decades. But if the replacement is going to work as you say I can see wiring switch on the dash that locks in the solenoid at my will regardless of throttle position.

Thanks much for your in put !
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  #13  
Old 04-16-2021, 11:13 PM
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Originally Posted by CDL View Post
All I know is how mine has functioned for decades. But if the replacement is going to work as you say I can see wiring switch on the dash that locks in the solenoid at my will regardless of throttle position.

Thanks much for your in put !
Or move the selector lever to "3" or "2", Einstein!!
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  #14  
Old 04-24-2021, 06:05 PM
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Originally Posted by Frank Reiner View Post
Or move the selector lever to "3" or "2", Einstein!!
LOL.

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