If the wiring is simply shorting out the coil on the positive side, then I don’t foresee any major problems with the MSD distributors and the kick down switch.  The only issue I’ve seen with an MSD ‘ready to run’ distributor is where the voltage supply had been resisted down rather than running the full twelve volts which caused an early failure of the module.  I would suggest talking to the MSD reps and asking about the potential for damage as a result of momentarily shorting out the system and if voltage surges or spikes are an issue with this.  I can speak from experience that the Mallory Unilite distributors do not like the kick down switches as those units did not like the abrupt changes in voltage that resulted from shorting out the ignition.


That sounds like a good alternative to using a governor.  I’m assuming a relay is being used in conjunction with the backup light switch?

Lorena, Texas (South of Waco)

I have an Overdrive in my 32 Ford. It's a Gear Vendors unit behind a 4 speed transmission. I was worried about the problems using reverse, so I ran the power to the OD thru the backup light switch. Anytime reverse is engaged, power is cut to the OD. 
I wonder if that could be done in the above discussed example, where the original wiring is not used?

I wonder if the MSD ignition would like the kick down switch?

Durham Missouri

I run a Pertronix II in my Merc and using the kickdown is no problem for it. I checked with Pertronix about this before I bought it. So I'll say so far so good. Your mileage may vary with other electronic ignition conversions.

I can understand the wiring and relay issues that crop up with the older factory overdrive cars.  The wiring and relay is bad on my ’50 and I simply wired the O.D. solenoid to a simple on/off switch.  The governor wiring was also bad so I had to take it out of the system too.  I do use the overdrive in that car a lot in town driving simply due the car having 4.27 rear gears and working that switch as I come to a stop just becomes part of the driving habit.
 
My ’55 on the other hand does still have the governor hooked up in a series with the solenoid with a toggle switch so it automatically drops out the voltage to the solenoid at low speeds and allows the transmission to freewheel when coming to a stop.  This switch basically stays energized all the time but because the governor is in the circuit, using reverse is unaffected with the switch being ‘ON’.
 
I’ll add that some of the electronic ignition conversions do not take kindly to using the kick down switch under the gas pedal.  By design, that switch when activated momentarily shorts out the ignition so the solenoid can disengage.  That ‘shorting’ design is hard on the converted ignition electronics so I typically recommend not using the kick down switch with electronic ignition conversions.

Lorena, Texas (South of Waco)

The relay, 6 and 12v, are being repopped. 5th Avenue Antique Auto Supply has 'em, as well as the solenoid. The kickdown switch is available from most old car parts suppliers. Another source is Van Pelt Sales. The cables are also available but it's easy enough to figure out the length and have one made up locally.

I had a 56 pickup(GMC) took out the 4 speed hydro and put in an overdrive 3speed. Since I didn't have all the stock parts I used a PTO cable for the engaging lever and a toggle switch for the solenoid. Even tho it was not recommended I even used 1st over just to screw with guys. I'd go thru all 6 speeds splitting as I shifted. Got pretty good at it. 2nd over was great in mountains and I could it from free-wheeling if I wanted. Good luck.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

I always ran the O/D's with factory wiring, including the kick down switch. Then I would put a toggle sw in to disengage it. The relay and switch can be difficult or expensive to find, and the wiring is a pain. And at least the 'birds had a spring loaded throttle link, so you could push thru full throttle and hit the kick down. I don't know where you find those these days. But it's really nice to the have the kick down if you need it, and also the drop at at low speed. Not to mention leaving it engaged and backing up.

Maybe those parts are still in the donor vehicle?

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

He should at least use the governor, that way he won't have to worry about turning the solenoid on and off all the time.

If at all possible I'd run it like it came from Ford. If not possible then I'd only use it with the solenoid on when on the open road.

Durham Missouri