Neutral safety switch operation?

[makrie]

I would appreciate a tutorial on the intricacies of the neutral safety switch on a 65 T-bird. First symptom, I move the steering column slightly to the right to engage the starter. I've done it so frequently I don't even think about it anymore. This last weekend a second symptom occurred, I couldn't get my convertible top up with the engine running. Later I duplicated the problem by playing with the shift lever.

I expected to see the shifter operating a set of contacts in the neutral safety switch but I also see two hoses which I assume are attached to a vacuum source. That I'm unfamiliar with and would appreciate your help understanding it's operation, adjustments if any, and recommending replacing or rebuilding the unit.

Thank you!

 

[makrie]

After further research I was able to determine the operation and next steps in addressing this common issue...can't find a way to remove the thread but some may wish to continue this anyway for the benefit of others...

 

[Popsashburn]

My 64' wants to engage the starter when I turn the key on, unless I move the steering column to the right. I've replaced the NS switch, with one from Macs (piece of junk) I'm very confused about the electrical. I've tried to study the wiring diagrams without much luck.

 

[makrie]

Just to be sure what you're describing...when you turn the key to ON, not START, the starter motor engages; and nothing engages if the steering wheel is pushed to the right?

 

[Terry64HT]

Maybe I can help a bit with the electrical. The neutral safety switch has 2 pairs of wires. One pair is for the backup lights, power in from the fuse panel with a splice at the connector to the windshield washer pump (backup lights and washer pump are on the same fuse). When the gear selector is in "R", the backup lights are powered.
The other pair is from the ignition switch and powers the coil in the starter solenoid. When the coil is energized, it pulls the contacts that close the circuit from the battery to the starter. The neutral safety switch only allows this to happen when the gear selector is in either "P" or "N". When the steering column is swung to the right, the neutral safety switch is inoperative.
I don't know if this is any help, but I wonder if you are wrestling with 2 problems, one being the ignition switch that is energizing the starter solenoid in the run position?
Terry
64HT

 

[Terry64HT]

I could do with a bit of help with the vacuum part of the neutral safety switch.
I've redone my parking brake and it now works as it should, including being released when the shift lever is moved out of park. But when I shut the car off, the parking brake pedal won't ratchet until the car sits for a bit of time. I assume it's because the vacuum has pulled on the motor that releases the brake, and is not venting properly when the engine is shut off. Where does this venting happen, and how long should it take?
Any help appreciated
Terry
64HT

 

[HeadacheGuy]

I honestly haven't looked at mine as the diaphram is bad and it is the only thing that doesn't work on mine but i used to work on similar ones quite a few years back. Can it be as simple as the lines reversed on the neutral switch itself? They do need to vent as you described and I believe that is the only place they can vent it. I thought the slide portion of the switch opened to atmosphere on the diaphram side and sealed the vacuum side when put in gear. I will be interested to see what you find as I am going to tackle this one after mine comes out of the body shop after the first of the year. I would look at it now and let you know but I am having a top put on it and won't see it back for a few days.

 

[Terry64HT]

I thought it would work as you describe, but I've tried the lines both ways and it makes no difference. None of the photos online show any sort of port to vent the vacuum in the places you would expect it to be. I've never had my switch out, and don't relish the thought of getting up under there, but it may be the only option. Of course I can always continue to wait for about 10 minutes after I shut the car off before applying the parking brake.
Thanks for the post. I'm still hopeful someone on the forum has one lying around and will take a look.
Terry
64HT

 

[arizman2]

I thought it would work as you describe, but I've tried the lines both ways and it makes no difference. None of the photos online show any sort of port to vent the vacuum in the places you would expect it to be. I've never had my switch out, and don't relish the thought of getting up under there, but it may be the only option. Of course I can always continue to wait for about 10 minutes after I shut the car off before applying the parking brake.
Thanks for the post. I'm still hopeful someone on the forum has one lying around and will take a look.
Terry
64HT

9 months later, still wrestling with your issue?

 

[Terry64HT]

I played with it for a bit and then went on to other things. Without taking the neutral switch out (something I'm loath to do), I don't know what my next step would be.
Perhaps a tee with a one way valve?
Terry
64HT

 

[sseebart]

It sounds to me as if you have the parking brake hooked up to a vacuum line fed from the "soup can" cannister, which is intended to hold vacuum after the engine is shut off (to power the door locks and trunk release for a time).

The parking brake (through the NSS) should be attached directly to manifold vacuum, which drops to zero when the motor is turned off.

~Steve

 

[Terry64HT]

Steve, sometimes I feel so dumb. Your answer is so obvious that I can't believe I made the mistake. You are correct, I teed into the line from the canister instead of the one feeding the rear vents.
Thanks for this
Terry
64HT