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1965 Switch Pitch revisited


crowvet

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My switch pitch and passing gear does not work. I have checked out all the old posts on the subject and still find myself with questions. I even have the wiring diagram that is a bit spotty. My car has been switched over to a Edelbrock carburetor. The plunger switch at the carb was disconnected. I reconnected it and with a test light had nothing but power going to it on the orange wire. I sprayed contact cleaner in it, and now I can here the solinoid on the transmission activate. Every thread I have read says that the white wire sends power to the switch on the transmission to activate the passing gear. I never get power to that white wire. What I have going on is the Black/white wire has power as well as the orange, when it activates the black/white wire loses power. The small micro switch at the back of the linkage is never activated due to wear or geometry of the linkage from the carb swap. With the carburetor plunger activated, I can manually click the micro switch and hear the solinoid activate as well. Does the micro switch at the rear of the linkage play any part in having passing gear? Or is it just a idle circuit for the switch pitch? Because if that is the case my car does not creep at idle or have any ill effect, so I would not be to concerned if it did not work, as long as I had passing gear.

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I am no mechanic…I will share how I “think” it works with the little experience I had. Hope the guru’s teach us both if I have it all wrong. 

 

A few months ago I was fortunate to have a transmission mechanic aquaintance make a house call to help me sort this out. What he showed me was that the micro switch on the throttle linkage sends power to SP/KD (switch pitch/kick down) switch any time there is any pressure applied to the gas pedal. 

 

So yes. My understanding is U need that micro switch to work. Otherwise the SP/KD will never recieve the signal 

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5 minutes ago, RockinRiviDad said:

I am no mechanic…I will share how I “think” it works with the little experience I had. Hope the guru’s teach us both if I have it all wrong. 

 

A few months ago I was fortunate to have a transmission mechanic aquaintance make a house call to help me sort this out. What he showed me was that the micro switch on the throttle linkage sends power to SP/KD (switch pitch/kick down) switch any time there is any pressure applied to the gas pedal. 

 

So yes. My understanding is U need that micro switch to work. Otherwise the SP/KD will never recieve the signal 

The contact on my micro switch is always in the open position, haven't quite figured out why. Seems like tension against the linkage makes it pull on. However my linkage has no forward mounted spring and doesn't pull hard enough to close them. Least that is what I am thinking the issue is

 

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The only forward spring I have is the factory one that comes up from below the micro switch. The spring hooks to a plate screwed to the throttle linkage mounting base on the firewall. 

 

My micro switch is cracked. I was still able to adjust it tho. It doesn’t take much movement to set it. Loosen the tiny screws & with throttle in the resting position push the micro switch forward until u hear the mechanical click of the switch. Tighten screws. Then test it by pushing rearward only on the vertical throttle linkage rod coming up from firewall. The slightest pressure on the rod towards the firewall simulates your foot pressing on the gas pedal. There should be movement between the vertical throttle rod & the horizontal rod that it attaches to. That slight movement is all u need to open the micro switch. 

 

Hope that makes sense. Most important, I hope I got it right. 

 

Guru’s wanna chime in?

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57 minutes ago, RockinRiviDad said:

The only forward spring I have is the factory one that comes up from below the micro switch. The spring hooks to a plate screwed to the throttle linkage mounting base on the firewall. 

 

My micro switch is cracked. I was still able to adjust it tho. It doesn’t take much movement to set it. Loosen the tiny screws & with throttle in the resting position push the micro switch forward until u hear the mechanical click of the switch. Tighten screws. Then test it by pushing rearward only on the vertical throttle linkage rod coming up from firewall. The slightest pressure on the rod towards the firewall simulates your foot pressing on the gas pedal. There should be movement between the vertical throttle rod & the horizontal rod that it attaches to. That slight movement is all u need to open the micro switch. 

 

Hope that makes sense. Most important, I hope I got it right. 

 

Guru’s wanna chime in?

I understood that very well, as I was just messing with it yesterday. Makes perfect sense, Thank you I will give it a try. I am assuming that you would want to adjust it with the choke fully open and on low idle step. 

 

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2 hours ago, telriv said:

Yes, choke fully open & at hot idle for PROPER adjustment.

 

Fianlly, a Guru chimes in haha

 

So how do u suggest PROPER adjustment for those of us (me 😬) without a choke? 

 

And “hot idle” I assume means to have the engine running at op temp at idle during adjustment of micro switch?

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Well, My switch appears to be adjusted properly. geeze once you wrap your head around how it works, it is so simple. I was pulling my throttle open from the horizontal linkage closest to the carb. To check you have to pull the throttle open from the rear vertical linkage. So now I suspect my passing gear issue is one of the contacts in the stator switch.

 

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9 minutes ago, crowvet said:

Well, My switch appears to be adjusted properly. geeze once you wrap your head around how it works, it is so simple. I was pulling my throttle open from the horizontal linkage closest to the carb. To check you have to pull the throttle open from the rear vertical linkage. So now I suspect my passing gear issue is one of the contacts in the stator switch.

 

LOL...yep....

Tom

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5 hours ago, telriv said:

Yes, choke fully open & at hot idle for PROPER adjustment.

 

32 minutes ago, telriv said:

As long as the throttle is closed in the idle position the engine doesn't need to be running. Just key on engine off. REMEMBER, DON'T leave the ignition on without running for any length of time.

 

I wish I was better at this stuff. I’m confused. I’m sure I’m the only one. Sorry for being so dense. 

 

I had my engine cold, engine off, key hanging on the hook in the garage when I adjusted mine. 

 

Can u pls help me understand how the choke, hot idle & ignition being on plays a part in PROPER adjustment. I’d like to get mine right too. Thx

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7 hours ago, RockinRiviDad said:

 

 

I wish I was better at this stuff. I’m confused. I’m sure I’m the only one. Sorry for being so dense. 

 

I had my engine cold, engine off, key hanging on the hook in the garage when I adjusted mine. 

 

Can u pls help me understand how the choke, hot idle & ignition being on plays a part in PROPER adjustment. I’d like to get mine right too. Thx

With the choke on, it positions your throttle linkage on a higher lobe to achieve the faster idle. In this position your throttle linkage is also basically propped open. So adjusting your switch in this position would be incorrect because your throttle is being held open by the choke linkage. You want the switch adjusted to the idle you have with choke open and car warmed up. The key being on allows you to hear the switch click when opened or closed.

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19 hours ago, RockinRiviDad said:

 

 

I wish I was better at this stuff. I’m confused. I’m sure I’m the only one. Sorry for being so dense. 

 

I had my engine cold, engine off, key hanging on the hook in the garage when I adjusted mine. 

 

Can u pls help me understand how the choke, hot idle & ignition being on plays a part in PROPER adjustment. I’d like to get mine right too. Thx

  If the throttle is off curb idle, as in fast idle, the kickdown switch is in a different position than it would be in curb idle. The kickdown switch is part of the whole system. Best to have all in a "normal" scenario so the switch pitch can be checked for proper function at curb idle as that is one of the intended purposes of the system.

  The key needs to be in the on position because the power to the system is key switched.

  Tom

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