OK, so I did some mods to the ignition switch on the 300D. I removed the entire switch assembly, pinned back the plunger that engages the steering column and re-installed the assembly.

Now the engine won't shut off when I turn the key to the off position. I know, I've read the postings, just switch the vacuum lines on the switch. But the engine won't shut off with them switched either. This worked very well before I did this work.

I shouldn't say the engine won't shut off; to be correct it shuts off after about 2-4 seconds. With the vacuum lines one way it doesn't shut off at all (that must be the wrong orientation) and the other way it takes a few seconds. I have checked, and the vacuum hard line to rubber line and rubber to ignition switch nipple connections are all pressed on very well.

Where should I look now? I guess maybe the short rubber line could have a leak made worse by my manipulations? Any other ideas?

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Mike Frederick
1986 300SDL, 240K+ miles
1985 300D KaliKar, 270K+ miles

maybe you are having a leak at the vacuum pump or vac lines...

Is your brake pedal getting hard ?

I'd check the vac lines.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

The only way to properly diagnose vacuum issues is to get a vacuum gauge/pump. Start with that if you don't have one.

__________________
1979 300D 040 Black on Black - 1985 300D Maaco job (sadly sprayed over 199 Black Pearl Metallic) on Palamino

http://i.imgur.com/LslW733.jpg

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