Stop light switch used for safety starter switch?

[39deluxecp]

Why not use the hydraulic brake stoplight switch for the safety starter switch?. Just connect the wires for the starter solenoid through the brake switch. Then the brake pedal will have to be depressed to start the engine.

[dmsfrr]

Unless the brake light wiring were isolated from the 'start' wiring with some additional parts or relays, stepping on the brake pedal would energize the starter solenoid, at the same time it turns on the brake lights.
A separate mechanical switch on the brake pedal would do it.


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[fordor41]

a lot of newer cars have/had switch on the clutch pedal. would only start with clutch depressed. may make an easier job on the clutch pedal.

[Daves55Sedan]

Funny you should mention that. A few days ago, my starter neutral switch failed, so I opened the hood, unhooked the two red wires at the bullet connectors and plugged the two together. Doing this bypasses the starter neutral switch. But it will start with the gear select lever in any position, which is okay in my case because no one else ever uses the car.
That switch is at least the 3rd or 4th repro switch I've had on it. This one only lasted a couple years.
PITIFUL.

[dmsfrr]

Originally Posted by Daves55Sedan

Funny you should mention that. A few days ago, my starter neutral switch failed, so I opened the hood, unhooked the two red wires at the bullet connectors and plugged the two together. Doing this bypasses the starter neutral switch. But it will start with the gear select lever in any position, which is okay in my case because no one else ever uses the car.
...

A similar round-about story...?
A previous owner left the NSS out of my '55 and bypassed it in the wiring, so I have the habit of always putting a foot firmly on the brake pedal before starting.
Went to start it one morning but the brake pedal went straight to the floor when I pushed on it. The reservoir on the one year old master cylinder was empty. The diaphragm in the brake booster had apparently gone bad during a drive the previous week and sucked all the fluid out.

Having a pressure sensitive brake pedal switch in the wiring to the starter solenoid along with the NSS might seem a bit unnecessary, but may not be a thoroughly bad idea either, depending on who's driving the car.
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[Daves55Sedan]

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In my view, the original idea the poster had of using the brake light switch to enable the start circuit defeats the whole purpose of the starter neutral switch.
The starter neutral switch had a dual purpose when used with the early Fordomatics. 1) the switch prevented allowing the engine being started in any gear except neutral, so that if the gear selector had been in drive or low, the engine would not crank. 2) the switch prevented allowing the engine to be started if the gear select lever was in park. The mfr wanted to prevent the need to shift from park-to-reverse-neutral in order to reduce wear every time the engine was started.
In later years, the Fordomatics had a more beefed up park pawl and had somehow overcome the reverse-to-neutral wear that was prevalent in the '51 thru 59 Fordomatics.
You might as well just bypass the NSS altogether rather than using another device which does nothing to fulfill the goals of the NSS. The only thing the brake switch would do is prevent the car from immediately lunging forward when the engine was cranked if the gear selector was engaged in the wrong detent. But if you did have this arrangement, might it be possible to break off a gear-tooth inside the trans or cause some other damage?