I researched this in the forums but could not find an answer.

My 1986 190D stays on for about 4 seconds after I turn the engine off. I am getting very good vacuum from the vacuum pump.

Also, when I apply vacuum to the shut off valve it holds and I can see the off switch drop.

I checked all of my vacuum lines and can't find any leaks. Locks are all working fine.

Does the vacuum line that is Brown/blue go to the ignition switch after passing through the firewall?

Any ideas?

Thanks!