Great topic to bring up. Sounds like something the manufacturers like to keep quiet.
So far it sounds like you are the expert on this subject. If your research shows this to be a problem, I would contact your nearest Ford dealer and see if Ford has come out with a change to corret the hazard. You are right in assuming that simply putting a new switch in only leaves you with the same problem, unless they have done something to correct it. Older systems used a vacuum dump switch attached to the brake pedal to cut out the Speed Control. It dumps the vacuum to the servo.
In looking at the diagram for the newer Speed Control, I see this switch and the circuit it is in, is used to power the Servo Clutch powered by fuse 13. Also I see that they no longer use the vacuum dump switch which did the same thing to the servo. Not sure why they did this, since I've never heard of a problem with the old method, probably, (that's "prolly" for you Texas boys
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[email protected] 2x" width="20" height="20" /> ), to make it more electronically sophisticated. There is still a electrical switch at the brake pedal to signal the Speed Control Servo/Amplifier Assembly when the brakes are applied and the one on the master cylinder is indicated as a redundant safety feature, in other words either switch is supposed to disconnect the Speed Control. Sounds to me like it is actually a hazard device. In my observation over the years, the more electronically dependent a system is the higher the failure rate. In this case potentially deadly to the occupants of the vehical.
Any facts that anyone has on this subject would be appreciated. Keep us posted on anything new you come up with.
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