I don't know what this switch is or what it connects to. Is this some kind of kick-down switch? Any help would be appreciated.
Is it attached to the throttle linkage? Looks like a kick down switch to me. I assume you've got a th400?
Yes it is attached to the accelerator linkage, looks like someone just cut the wires but don't know even where it connects too. Yes th400
As far as I know, that switch is not supposed to be there. That is a gas pedal kick down switch for the THM400. It is actuated by the gas pedal in 68+ cars? Looks like someone retro fitted it to the early style linkage since the early style gas pedal would not work with that switch. Wiring? It is so simple. All it does is pass 12 volts to the transmission. One wire gets key on 12 volts. The other wire goes to the transmission case connection on the driver's side.
Ok this is the switch that seems to be connected to trans but still have a problem with kick down, just does not work. Larry maybe your right and some one retro fitted it and are using this other switch ??? Hmmmm
That tiny switch at the top of the throttle arm is for a switch pitch, or variable pitch, torque converter. It switches on the high stall mode at idle as the throttle arm is closest to the firewall. As soon as you touch the throttle, the arm moves forward and allows the tiny button in the switch to spring forward, cutting off the voltage, and tighten the stator for low stall (rated about 1800 rpm). The whole purpose of this is to allow the engine to idle freely without the drag of a tight converter, almost like being in neutral. The larger boxed-in switch mounted on the linkage (not the one shown in this picture), would kick in the passing gear at a point of forward movement of the linkage and also switch the converter into high stall (2800 rpm) for acceleration and performance. The Super Turbine400 and ST300 transmissions for Buicks and Cadillac's used these from 1964 to 1967. The "big switch" you have is for 1968 and up, non switch pitch TurboHydromatic TH400. That is what I now use in my 1967 GS after changing to a JW 3500 stall 9.5" converter from this site. I sold all my switch pitch stuff...converter, pump, switches, wires. If you have this original stuff, carefully pack it up or put it back into functional condition. It's rare stuff and worth money. Check this out!!!
Does that bigger switch operate the passing gear?? The passing gear right now does not work at all. Just trying to find out why or do I need to replace any of these switches with something else?
CORRECTION: I just looked at the additional photo you posted above and your big box switch has an extra small wire plug that mine does not have. My later model has the big plug only. Maybe that is for a switch pitch? or an idle solenoid?, I don't know. Look at your transmission and see if you have a two tab or single tab connection just above the oil pan on the driver side. Switch pitch had 2 brass tabs in one little round housing. Also look at the ID plate on your tranny. It may have a date on it and other info. NOTE...The little switch I referred to "at the top of the throttle arm" is close to the firewall and has two chopped off wires. That is the idle switch I referred to in post #8. And, yes the wide black plug is for kick down to passing gear.
That switch is NOT SUPPOSED to be there. There is no doubt about that. Someone put it there. Looks to me like that threaded rod is supposed to actuate the switch, does it do that when you open the throttle wide by hand? If so, next step is to check the switch with a meter to make sure it is working. Then, check to see if there is 12 volts on one contact with the key on. If so, trace the other wire and see if it goes to the transmission. If so, check to see if you get 12 volts at the transmission with the key on, and actuating the switch by hand. If you are getting 12 volts at the transmission, and no kick down, listen for the solenoid click when you apply 12 volts from the battery to the transmission. No click, you'll need to drop the transmission pan to look at the wires inside the pan. You may need to replace the down shift solenoid. If your transmission has only one contact, odds are it is no longer a switch pitch, and that add on switch is for the kick down. This is what the switch pitch linkage is supposed to look like.
Ok Thanks Larry will check it out and let you know, Looks like it was a switch pitch at one time and then someone tried to convert it. Lol another butcher job to fix.
I'm sure the SP transmission is long gone. That bigger plunger switch in the picture I posted above controlled the switch pitch AND the kick down. As Gary mentioned, the smaller switch up near the firewall put the SP in high stall at closed throttle. Off idle, the SP went to low stall, above 60% throttle, the plunger switch put the SP in high stall, and at full throttle, it kicked the transmission down. Looks like maybe the PO rigged that later model switch up when he replaced the transmission. It's fine if it works. Open the throttle by hand and see if it slides the switch all the way closed.
What year is the car (switch pitch were 65-67) and what year is marked on the trans plate? Your switch is the partial remains of a switch pitch factory control. If your trans only has one tab, its currently not an operational switch pitch. Since the rest of the control is gone, you also have no electric kickdown. A simple 2 wire kickdown switch can be added, I use the 70s kind mounted just above the gas pedal. If the trans is a switch pitch, you can add a control; the factory type will work but only activate at idle or near full throttle. I like the electronic type which works in any range. Bruce Roe
Ok Larry I checked the switch, it opens and closes, It had voltage when key is on, and voltage when I slid the switch to the open position. I also checked the voltage going down to the trans which had none and no clicking going on. Checked the other end of the plug and had voltage. Someone connected the wrong side of the plug to the sensor on the trans. It now clicks when there is voltage going to it. I haven't test drove it yet but sounds like the problem has been solved. I will have to let you all know if its fixed and if I should just leave this switch or put in something else in place. Thanks
If you hear the click inside the pan, that is the downshift solenoid. It will kick down. You can leave the meter connected to the switch and manually open the throttle to see when the switch closes relative to throttle position. If the switch works, I would leave it.
Hi Bruce Thanks for the reply The car is a 1967 GS 400 I will have to get under the car again to get the year off the plate, Think I checked it while it was out and it was a 67 I believe BA But will check again and let you know.
I believe you will find your remaining switch closes at idle, not near full throttle; if so it can't provide the missing kickdown function. Kickdown is activated with 12V applied to the lower electrical tab on the trans. A switch pitch trans also has an upper tab, sort of forms a T. If that is missing on your 67, the trans has been modified or swapped. Bruce Roe
