I have a 68 cdv that I have replaced the neutral switch on. The vacuum line that has a wide white stripe connects from the switch to a vacuum source under the hood. It has been disconnected since I have owned the car. I can just hook it up to one, but wondered if anyone knows where it originally went?

Thanks.

Newer models had the vacuum valve for the parking brake release built into the neutral safety switch. See if the parking brake release has a little vacuum canister hooked to the release linkage.

Thanks Ape Man,

I do have the switch connected to the brake release. Thankfully the vacuum hoses to the switch can only be connected one way. It is the vacuum source location under the hood that I can't figure out. Again, I could just hook it up to one, but if possible, would like to connect it to its original source.

Thank you

I don't know exactly where but there is usually a vacuum tank somewhere under the fender well. The tank is fed from the intake manifold or carbonator base through a one way valve. The AC and neutral safety switch vacuum had feed from the tank so that the AC doors would work properly when engine vacuum was low like when driving up a long hill.

I have a 68 Convertible DeVille that has broken 2 of the neutral safety switches. Where can I buy one?

I got mine at Arizona Vintage Auto Parts. Google it. It was $100.00 for a good used one. Put it in and it works great. I still can't figure out where that vacuum line terminates. I originally thought it was hooked to a vacuum source but now I'm not so sure. The istallation of the switch is pretty straight forward.

On the fire wall, just to the left of the master cylinder vacuum booster, there should be a plastic vacuum tank. The problem with this tank is that when people try to pull the vacuum hose off of it, the little "tit" that the hose goes onto will break off. The only way to safely remove the hose from this tank is to cut it off with a utility knife and then peal the hose off carefully. If the tank is missing, you can search eBay, but whenever I have seen them on there, they go for big dollars. There were a few versions of the tanks, and the vacuum line from the engine will either be under the one that goes to the dash, or it is one of the other type, it will be on the opposite side of the canister. Prior to that, Cadillac use what looked like a large tomato soup can vacuum canister.
I have a problem with my 1969 where it will only start in neutral, but not park. I haven't looked at it to see if it is out of adjustment, or is broken. What were the symptoms of your car prior to replacement of the switch?
Thanks..........
Junk....

Thanks for the info on the vacuum tanks. I will check it out. Your switch might just be out of adjustment. The screws on the switch can be loosend so you can rotate the switch (slightly) clockwise/counter clockwise. With the gear selector in reverse, and the key on, I used the backup lights as a guide to tell when I was close. It took me a few tries but I eventually got it working properly. Before your loosen the switch, try to start the car in park and jiggle the gear seletor in Park to see if you get a connection. That worked for me until I adjusted it.
Also, if you need a new one, the replacement Neutral switches for 1969 and up are much less exspensive than 1968 and older.

I finally figured out what the capped off vacuum line is for. I guess the 1968 Cads had a "dash pot" mounted on the carb that engaged when the ac is turned on and speeds up the engine idle. Mine was removed long ago.

If your 1968 is like my 1969, on the left side of the carburetor, there is an electric kick up device to increase the engine speed when the air conditioner is on, and a stand alone dash pot that keeps the throttle from returning to idle too quickly and allows the throttle plate to close slowly, to prevent erratic engine performance. On the right hand side of the carburetor, there is a vacuum control that will increase the engine speed by holding the throttle plate partially open when the engine is cold, and the carburetor chock plate mechanism is in operation. As the engine warms, the choke high idle plate will slowly open, and the stepped throttle shaft plate will slowly come off each step until it reaches normal idle. I believe what you might be missing is this idle control. If you need pictures, please PM me with your email address.... Junk.....

the white stripped hose connects to the idle speed up diagphram on the back passenger side of the carb. i have a 69 cdv. and i am trying to figure out the vacuum maze myself. it is a very small diameter hose.