overdrive on a toggle

Can anyone shed light on wiring my overdrive  to work from  a toggle switch?
thanks mucho


  • allanallan Posts: 197Member

    hot to fuse, then to toggle switch.  toggle to large terminal on overdrive solenoid.

    Recommend using a relay to supply battery power to relay.  in that case wire in relay to battery power and use toggle to actuate relay wired to overdrive solenoid.

    have this setup on all my cars.

  • 2nevets2nevets Posts: 116Member
    So that bypasses everything correct? and when I want it to come out of overdrive I just shut the toggle off ?
  • 2nevets2nevets Posts: 116Member
    So does that take the governor out of the equation I'm really not sure how the overdrive works because I haven't started it yet I'm sure it's not that complicated but I'm just looking for the simplest solution
  • 7XPacemaker7XPacemaker Posts: 330Senior Contributor
    Also remember that you can't put the car in reverse unless the overdrive is toggled off. If you leave the overdrive in while at a red light, you will be starting out in second gear. I had this setup on mine as well.
  • Jon BJon B Posts: 6,994Administrator
    Interesting.  I actually have my OD kickdown wired to a momentary-contact pushbutton switch mounted beneath the dash (as opposed to a toggle switch).  So, whenever I need to downshift to third gear, I depress the button while releasing the gas momentarily. 

    For many years I had a plunger kickdown switch mounted under the accelerator and it worked fine, but some time ago the car started backfiring whenever I would push the gas pedal to the floor.  (No idea why that was happening).  So I re-wired the circuit to incorporate the pushbutton, and no more backfire.
  • GeoffGeoff Posts: 3,714Senior Contributor
    When you say "backfiring", what is actually happening is that the unburnt mixture that is  sent into the exhaust, for the power strokes that are shorted out, are igniting and exploding out the exhaust pipe. 
  • Jon BJon B Posts: 6,994Administrator
    edited February 8
    Agreed, Geoff.  But I wonder why this began to happen all of a sudden, after almost 40 years of working fine?  One possibility is that I changed to a much heavier transmission oil (140 weight, I recall).  I wonder if that got into the solenoid and made the rod move in and out slower, thus causing the delay in the "momentary" shorting of the ignition.  Because the ignition paused so long, the gas built up in the exhaust pipe.  Then when the ignition was finally restored....bang!  I have just switched back to a modern, lightweight transmission oil (it's so thin that the gears clash every time I shift) but I haven't restored the pedal-activated kickdown switch yet, to see if the kickdown no longer causes backfire.

    UPDATE: I restored the gas pedal kickdown switch, and the OD works like a charm.  No more backfiring.  I can only think it's because I'm now back a modern, lightweight oil in the transmission, so that the solenoid plunger no longer sticks (and thus there is no delay in the shorting of the ignition).  

    (I apologize for hijacking the threat, briefly!  Just disregard me!)

    Alan, is the toggle switch spring-loaded, or does it remain in the "on" position until you flick it back the other way?
  • 2nevets2nevets Posts: 116Member
    edited January 30
    So the solenoid always has to be energized or needs a constant 12 volts going to it in order to stay in od ? 
  • GeoffGeoff Posts: 3,714Senior Contributor
    Yes, or 6 volts if original.  The solenoid has two coils, a heavy one for the pull-in, and light one for the hold in.   Once the relay is activated the  solenoid  pulls in, and a pair of contacts internally opens the circuit to the pull-in, and closes it for the hold-in.
  • 2nevets2nevets Posts: 116Member
    edited January 31
    what the heck am I thinking? 12 volts 
    It's tough getting old 
     okay I appreciate all the help
  • 2nevets2nevets Posts: 116Member
    works like a charm!!

    I used a headlight relay and ran the ground terminal to a motor cycle toggle located on the sifter handle and the wire from the toggle to ground. The relay is activated when the ignition switch is turned on. I've been using this set up on my 46 Brougham since 1984. I have a Stude truck wired the same way except I wired the governor into the system so at low speeds the governor cuts out the overdrive and that solves the reverse problem. I've been using this set up since 1996. Split shifting the gears is fun.

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