Wiring of od kickdown

zoegrant

zoegrant

Well-known member
When I throttle down with OD cable pushed in the engine quits on me and the minute I remove my foot from the throttle the car runs good but no overdrive.
I have bench tested the relay and the solenoid and both are working properly. This has to be a wiring issue....where should look to solve this ?
 
It sounds like your OD kickdown switch is not working properly or the contacts are too wore out. In principle, once you press the accelerator pedal to the floor this causes a "momentary" ground of the distributor lead so that the engines cuts out its load on the transmission so things in the OD tail housing can disengage. However, the break in the ignition circuit is to be temporary and I mean like split second.

Do you have any OD manuals? Borg Warner made quite a few back in the day. I have copied a few to digital files and have them available on a CD that I sell for just about what it costs me to make them. If you do some sleuthing you may be able to find some of those manuals around the web.

I may have one or two files small enough to send via email if you need one. The test procedures, wiring diagrams, troubleshooting guide, etc is excellent.
 
This is from the 1953 Ford shop manual but it still applies as BW did not change the operation of their OD's throughout production.

USE OF KICKDOWN SWITCH CUTS OUT ENGINE

"If the engine stops completely when when the kickdown switch is operated, disconnect the orange wire at the bullet connector and press the kickdown switch. If the engine now continues to run, check and repair the insulation on the orange solenoid wire. If the engine still stops replace the kickdown switch or the switch to solenoid wire."

If your wiring colors are different the solenoid wire should be connected to the lower contacts on the switch.
 
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Hi Rev...I do have quite a bit of info on the OD systems...plus I have the 55 Ford wiring schematic ….The kickdown switch is fairly new but I will remove it to bench test it.
The 55 schematic shows that the throw switch (white wire red tip )goes to the + side of the coil.....is that how yours is hooked up ?????
 
This is my diagram... I replaced all of the wires and made my own so my colors do not match yours (or anyone else's I'm sure).

The only two items that are different - I mounted a modern relay just behind the driver's side sheet metal vent panel (next to the radiator). However, the same leads on the original relay setup go to the same terminals on my "modern" setup.

Beyond the kickdown switch, is your governor indeed grounding when coming up to speed? (Like 27 mph I believe)
 

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Rev..my wiring is basically the same setup as you except that the two rear wires on the KD switch are reversed....I will set up exactly like yours tomorrow.
Hard to tell if the gov is grounding out around 27 mph. My hearing is not too keen so hard to hear the relay click with the road noise when driving. I will try to set up a test light that will go on when driving. I will keep you posted.
 
The ground path breaker in the operating solenoid may have a problem or a wire in the kill circuit may be shorting to ground. When the kick down switch is activated, all it does is open the circuit on the holding coil then closes the ignition coil kill circuit so the transmission will drop out of overdrive. The moment that it drops all the way out, a set of points inside the solenoid opens and allows the ignition coil back on line. It's not hard to take the outer can lid off and check out the functions inside the solenoid. There are two sets of points so you have to figure out which one grounds the coil and which one opens the circuit on the pull in coil. The terminal connections inside will generally lead you to which terminal's points to look at. The solenoid has a pull in coil and a holding coil. As soon as the unit pulls the transmission all the way into overdrive it kicks out the pull in coil function but leaves the holding coil on line. This feature saves a lot of electrical power usage that would be unnecessary to the operation of the system.
 
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I will remove the solenoid again tomorrow to check both sets of points...funny thing is that the solenoid bench test ok but it does not work when attached to the ******...when bench testing the solenoid it is attached to a 6v battery I will post the condition of the points.
 
zoegrant said:
I will remove the solenoid again tomorrow to check both sets of points...funny thing is that the solenoid bench test ok but it does not work when attached to the ******...when bench testing the solenoid it is attached to a 6v battery I will post the condition of the points.
Click to expand...
It may be unlikely but is there a chance it isn't grounding somehow, or binding on something, when it's installed???
 
Will run grounding test before removing the solenoid from the ****** to check the points.
I will report back.
 
OK. …....I am thinking the problem is in the ****** and here is why I am saying this..... Each time I depress the kickdown the engine cuts out. All wiring appears correct. The gov, the kickdown, the relay and the solenoid all bench test good.... but when I install the solenoid into the ******
the solenoid will not engage. When it is still in the car and I disconnect all the wires from the solenoid and hook the battery to the solenoid it still wont engage. When I remove the solenoid from the car and bench test it immediately engages.
When testing on the bench with a battery it will only engage when I attach the battery cable to the ear of the solenoid and the other cable to #4 terminal on the solenoid.
IT WLL NOT ENGAGE WHEN CABLES ARE ATTACHED TO THE #6 AND THE #4 TERMINALS OF THE SOLENOID. Should it ??????
COULD IT BE A GROUND PROBLEM ???
 
Troubleshooting

The Borg-Warner overdrive transmission combines both mechanical and electrical components. The mechanical components are very stout and as long as the transmission AND THE OVERDRIVE unit is filled with gear oil (see maintenance below) the only problems should be electrical, which are very easy to trouble shoot.
Take an OD truck out for a test drive with the OD cable pushed in, if it freewheels above 28 mph (and you don’t feel the automatic shift) the trans is OK but there is an electrical problem.

I know nothing of the OD system, but need to learn for my own OD down the road. This is from Fordification Tech. Maybe you have already seen this, but I don't see it mentioned anywhere.
 
Back in December you said the OD was working perfectly. There should be no wiring problem if nothing has been changed. A mechanical problem with the transmission should not cause the engine to die when you actuate the kickdown switch. Did you disconnect the wire between the solenoid and the kickdown switch like the manual troubleshooting suggested? If so and the solenoid was the problem it should correct the engine kill situation.
 
40cpe..back in the winter I did have the OD working, then it stopped working. If I remember correctly I though the issue was related to the pawl not seating in the blocker ring. I somewhat remember jacking the rear end up and with the OD cable pulled out and the car in neutral I rotated the drive shaft a revolution while I had the solenoid somewhat loose and that was supposed to line the pawl and blocker ring up. But in reading further on this I see I did not quite do it right. Will try again.
I really think that it is not electrical because I have checked the wiring so many times and all appears good. The only thing that appears not to work is the solenoid which works perfectly when bench testing but not when in ******. If the blocker ring is turned in any way the pawl will not engage 100%. I know the plunger engages the pawl so I suspect the problem is with the pawl engaging the blocker ring
 
Ground path is the the component attachment to the transmission. Power for the solenoid connects to the #4 terminal just like the diagram. The #6 terminal is for the coil kill circuit just like the diagram. The kick down switch opens one circuit and closes the other when pushed. The firewall relay is the main control switch for the system and the governor switch controls the on speed for the system.

Study the diagram and most of the function becomes apparent. As was mentioned, if it was working before and nothing has been altered or changed then all the wires should be properly connected.

When you push the kick down and the engine quits, any part of the coil kill circuit is suspect. Wire from coil to kick down switch, the kick down switch itself, wire to #6 terminal, or the control point set for the circuit inside the operating solenoid are all suspect until they are eliminated as a possible fault.

The only other suspect thing would be that the solenoid is not mechanically dropping out of overdrive like it should since that is what brings the coil back to life. It has to drop all the way out to open those points that are allowing the coil to stay grounded. You should only feel a split second of coil interruption when its dropping out before it takes off in 3rd gear.
 
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rotorwrench….that is a good explanation of the OD circuit.
With the overdrive cable pushed in the ****** does not go into overdrive but does free wheel. I believe my kick down does not work because the ****** never gets into overdrive, I believe that the ****** never goes into overdrive because the pawl is not allowed full engagement into the blocker ring. (see my post #16) Somehow I think the blocker ring moved out of alignment not allowing full engagement of the pawl into it.
I will continue to check continuity in all wires to insure I do not have an internally damaged wire. All the wires outsides look good.
 
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Don't know if you've tried this already, but for another test you can bypass the control circuit by jumpering from the battery to the solenoid. Put a toggle switch where you can reach it while driving. With the cable pushed in get up to 27 mph or higher, turn the solenoid on and lift off the gas. If it goes into OD you'll know that the mechanical functions are working. Be sure to turn the solenoid off before taking off from a stop.
 
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