[27Tall T]

I've just completed the rewiring of my '32 with a wiring kit from "Its A Snap". I've wired other cars with Painless, Francis and a few others and have had no problems. This one has me stumped. When I place the selector in Park and turn the ignition key to start, the motor won't turn over. When I place the selector into neutral, the motor turns over. I'm running a 327 with an HEI, a 700 Trans., and a 1975 Cadillac Tilt, telescopic wheel. I've replaced the neutral safety switch several times and still no action in Park. I've checked for continuity at the ignition switch and find that the purple wire that goes to the NSS is energized when in neutral. It's also energized when in Park, but the NSS cannot complete the circuit as it does not have an extra set of contacts in the Park position (I took the switch apart). Is there any possibility that there is another wire missing that will engage the starter when in Park. Hope someone has an answer.

[vicrod]

It appears that your covered the electrical side of the problem.
You must have a mechanical issue with the tab on the shifter shaft that actuates the NSS.
Could it be something as simple as an adjustment to align the tabs with the contact?
The NSS will have only one set of contacts but will be actuated by 2 different tabs (cams) on the shifter shaft, one for the neutral position and one for the park position.

vicrod

[75gmck25]

It may be the adjustment on the ignition switch (which is mounted on the lower column), or something wrong with the switch. It could also be the rack and rod mechanism that runs down the column from the key to the ignition. The rack part that connects to the end of the key tumbler is made of very lightweight metal, and it can crack or break.

Move the key between positions and see verify that the rod moves up and down the column exactly in synch with the key turning. If not, then troubleshoot the rack and rod.
Then loosen the two bolts that hold the ignition switch to the column and slide the switch up and down the column to see if it can be adjusted so both Park and Neutral work. If that does not work, then replace the switch.

Bruce

[27Tall T]

I've checked the rod going down to the ignition switch and it moves energizing the switch. I've loosened the screws holding the switch and moved it ever so slightly, as there is very little movement there. This still did not make any difference to the cranking. I've checked the wiring diagram of a Cadillac and it appears that they have another wire that bypasses the NSS. In other words power coming from the purple wire from the NSS can go through the NSS or bypass it and go straight through to the solenoid. This way the NSS will work when in neutral and it will be bypassed when it's in a Park position. To me this sounds a little weird, but that's what the diagram says. There is no provison in the wiring kit for this extra wire which bypasses the NSS. Anybody have an explanation?

[35terraplane]

Originally Posted by 27Tall T

I've checked the rod going down to the ignition switch and it moves energizing the switch. I've loosened the screws holding the switch and moved it ever so slightly, as there is very little movement there. This still did not make any difference to the cranking. I've checked the wiring diagram of a Cadillac and it appears that they have another wire that bypasses the NSS. In other words power coming from the purple wire from the NSS can go through the NSS or bypass it and go straight through to the solenoid. This way the NSS will work when in neutral and it will be bypassed when it's in a Park position. To me this sounds a little weird, but that's what the diagram says. There is no provison in the wiring kit for this extra wire which bypasses the NSS. Anybody have an explanation?

I wired a car for a guy a long time ago that had a cad column, his did the same thing I could not get it to burp in park. I was using a Enos board so I don't think it has anything to do with the board. I called Denny Enos and he had me try everything. I tried to get the guy to change columns, we finally just left it to start in neutral. I didn't really like that but that's what he wanted, I made darn sure it didn't get power when in gear.

35terraplane.

[27Tall T]

Is it safe to assume that the Cadillac column has some quirk that causes this problem? I thought that all GM columns, when it came to ignition, were pretty much wired the same way, exceot for some additional wiring for the optional accessories.

[39 OLDROD]

Originally Posted by 27Tall T

I've just completed the rewiring of my '32 with a wiring kit from "Its A Snap". I've wired other cars with Painless, Francis and a few others and have had no problems. This one has me stumped. When I place the selector in Park and turn the ignition key to start, the motor won't turn over. When I place the selector into neutral, the motor turns over. I'm running a 327 with an HEI, a 700 Trans., and a 1975 Cadillac Tilt, telescopic wheel. I've replaced the neutral safety switch several times and still no action in Park. I've checked for continuity at the ignition switch and find that the purple wire that goes to the NSS is energized when in neutral. It's also energized when in Park, but the NSS cannot complete the circuit as it does not have an extra set of contacts in the Park position (I took the switch apart). Is there any possibility that there is another wire missing that will engage the starter when in Park. Hope someone has an answer.

You say you have continuity all that means is its the same wire do you have 12 volts when the switch is in the start position in both park and neutral? if you don't then some thing is not adjusted. I wood not think GM would want a caddy to not start in park but who knows . I don't know how the nss fits on yours but some can,will go on upside down by that I mean with the tabs on the wrong end. With your ear close to the switch you can hear it click when the tab passes it. Good luck as I know some thing like this can be a PITA.

OLDROD

[35terraplane]

Originally Posted by 27Tall T

Is it safe to assume that the Cadillac column has some quirk that causes this problem? I thought that all GM columns, when it came to ignition, were pretty much wired the same way, exceot for some additional wiring for the optional accessories.

It is not safe to assume anything! Like I said I only found it in one cad column, I had put them in before with no trouble and after, Like 39oldrod said and I agree, you wouldn't think GM wouldn't want it to start in park, I see no reason not to.

35terraplane

[27Tall T]

Sorry to get back so late, but still working on the electrical problem. I've tried different things like moving the ignition switch, replacing the ignition switch, and tracing wires. Still no "burp" in park. Neutral is still the same, it works. To get a better understanding of the ignition system, can someone show me and explain a schematic of the GM starting system (mid '70's). I cannot see how the starting system works when you're in Park, as the NSS is not used in this mode. I get voltage coming down the purple wire to the NSS when in neutral, but when you shift to Park, the purple wire is also live, but the power goes to where? The NSS is not in the circuit at this point. There has got to be an explanation and the only thing that I can think of is that there is another circuit or a wire missing. I'm determined to find the solution, one way or another. Query...is there a GM neutral switch that has a set of contacts in Park and in Neutral? Just a random thought.

[35terraplane]

Originally Posted by 27Tall T

Sorry to get back so late, but still working on the electrical problem. I've tried different things like moving the ignition switch, replacing the ignition switch, and tracing wires. Still no "burp" in park. Neutral is still the same, it works. To get a better understanding of the ignition system, can someone show me and explain a schematic of the GM starting system (mid '70's). I cannot see how the starting system works when you're in Park, as the NSS is not used in this mode. I get voltage coming down the purple wire to the NSS when in neutral, but when you shift to Park, the purple wire is also live, but the power goes to where? The NSS is not in the circuit at this point. There has got to be an explanation and the only thing that I can think of is that there is another circuit or a wire missing. I'm determined to find the solution, one way or another. Query...is there a GM neutral switch that has a set of contacts in Park and in Neutral? Just a random thought.

What happens with the nss is you have power coming in, you have a tab that completes the circuit when you have it in park which will let the power go through to the start circuit. When you are in any of the gears there is no tab to complete the circuit so it will not start. neutral has a tab also so you can complete the circuit. The whole reason for the NSS is to keep the car from moving when you start it, which I'm sure you know. Now column mounted ignition switches MAY identify connections by letter/number sequence rather than color. usually not all terminals on factory switch will have to be used.
Like I said in a post before this I had a cad column that did the same thing, I wanted to fix it but the person I was wiring the car for didn't.
You can only move that switch a small amount, i think you said you changed switches. If you have power coming through when it is in neutral and not park I would say the tab to complete the circuit is broken.

35 terraplane

[27Tall T]

Thanks 35terraplane for the info. I'm really trying hard to understand all this, but I'm totally confused. When it is in neutral there is power coming to the switch via the purple wire (GM color). It crosses the contacts in the NSS and then to the starter, which it engages. When it is in Park, and I turn the key to start, power again comes to the neutral switch via the purple wire, but it cannot complete the circuit as there are no contacts in the NSS to send it to the starter. I've used my ohmmeter and found 12 volts+ at the NSS on one side in park, but that's it. If I cross both wires at the switch, when it is in park, it'll crank over. I don't think that the column is at fault as I get voltage, regardless whether it is in park or neutral, where it should be. This is what's causing me to lose what's left of my hair. Any additional comments would be greatly appreciated.

[27Tall T]

Okay, what do you mean by a tab and where is this tab? Is it in the column itself or in the NSS or in the ignition switch? Thanks for the reply.

[timothale]

I had trouble figuring out why a power window wouldn't work. The relay had corrosion so there wasn't enough amperage to operate. It all checked out ok with a test lite and meter, I used a hot 10 gage wire from the battery and it worked. I cleaned the relay connections and last time i saw the truck they were ok.

[35terraplane]

Originally Posted by 27Tall T

Okay, what do you mean by a tab and where is this tab? Is it in the column itself or in the NSS or in the ignition switch? Thanks for the reply.

If you could draw on here or have the program to draw it would be easy.
Ok when you turn the key to start the car, weather you are in park or neutral you will get power to the one side of the NSS. NOW just to help me explain this let's say on the bottom of the Nss you have a bump where the power comes out to go to the starter, inside the column when you move the shift lever it moves to each gear ,now when it is in neutral right under the Nss switch where the bump is you have a ball that has a spring under it, which pushes that ball against that bump which will complete the circuit. when you put it in any gear there is no ball to finish the circuit, so you can't start your car in gear. Now in your column, when you put your shift lever in park there seems that the ball is not there so you have power going in but no way to complete the circuit. Now as far as it being spring loaded balls, that is fiction , it was just to help explain how it works so you understand it. That's why people have trouble wiring cars that are not use to it, wiring diagrams can be over whelming, many people get very mad and confused real easy from it. and when you look at the factory diagrams they have all the jumpers and inside of switches and you don't need to see that.
Some of the after market boards go the other way and make it too simple, and it's hook this number wire here and that one there and you have no idea what you are doing, you sure don't learn anything.
Anyway that is why you have no power on the other side, And the way I read your post, you jumped the NSS in park and it turn over. So i would say if I understand you right you have the peice broke that makes the circuit complete.

35terraplane
I read through this I didn't say the bump was metal

[39 OLDROD]

Are we talking about a GM NSS or after market LO-CAR,B&M or what? they all are a little different BUT the one thing constant is that if the wire going in to the NSS is hot and hot coming out to the starter it will run IE. start in what ever gear it is in.It should only be hot coming out of the NSS to the starter from the start position on the int. switch in park and neutral. hope this helps as I don't know to make it plainer.good luck

OLDROD