I've replaced my ignition switch two times . . . the first one was a URO switch (enough said) and the one I have now is from Advance Auto.

My Question Problem:

The vehicle starts and runs fine. I drove Delilah (that is the name my wife has given her . . . and honestly, it fits!) home . . . when I came outside to start her back up tonight the key did not spring back from the start position . . . I had to manually turn it back (it only did this one time, it has "worked" find since).

After this happened though I noticed that the fuel guage and temp sensors quit working. I also had the pusher fan wired to turn on with the ignition switch and this was no longer working either . . . I was in a situation where I had to drive her (had to get my kids from daycare) and the alt/batt light came on after about five minutes of driving.

I have no turn signals or brake lights, temp or fuel guages or glow plug light . . . The Clock, Radio, Dash and Instrument Cluster lights work fine as well, but the ALT light is also on.

The Alternator was replaced about a month ago appears to be charging just fine (I drove it 20 minutes home with no dimming of the headlights and she started up "normal" when I got home and re-started her).

No fuses are blown and since I had the pusher fan wired to come on when the ignition switch was on I am assuming the switch has gone bad (again).

I've had the ignition lock out three times and replaced the switch twice . . . just want to make sure I'm on the right track before I spend another hour on my back with my legs up over the seat (in a different situation that might not be the case ; )

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1982 240
460,000 miles total
140,000 on Rebuild

Multiple items not working at the same time usually indicates a problem with one of the fuses. On these old cars, the fuses a lot of times look good but are actually bad. Replace them before attempting anything else. Hope that helps!

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1983 300 Turbo-"Nora"
1983 240D Auto "Lucia"-slowest on earth-1st love
1985 300 Turbo-Blue Goose-slowly plucking parts

http://i117.photobucket.com/albums/o...ly15/mbsig.jpg

Did you pull the cluster to work on the ignition? If so, there's probably a loose connection, pinched wire and/or bad ground in the circuit board that got "flexed."

I presume you mean "no turn signal and brake INDICATOR" lights on the dash, not outside the car.

These shouldn't affect the actual operation of a fan, though. When you say "pusher" you're talking about the aux fan in front of the condenser?

I did pull the cluster . . .

I have no brake lights at the rear of the car . . . no turn signals (either indicator in the cluster or at the rear of the vehicle)

Fuel gauge is not working, neither is the temp sensor or the GP indicator light.

The "ALT" light also comes on after about five minutes of driving. I've been told that the only two things that can cause the "ALT" light to come on are the Alternator itself and the ignition switch . . . the alternator is a rebuilt Bosch unit that is less than a month old.

This all happened right after the ignition failed to return to the "run" position from start position. My hunch is that I have (again) gotten ahold of a cheap ignition switch. I'll be ordering one from Mercedes (unless there is a source here) in the meantime I have one more ignition here at the house . . . I'm going to replace it and see what happens.

Oh, and, the fuses were the first think I checked : )

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1982 240
460,000 miles total
140,000 on Rebuild

Maybe it's not the switches, but the plug on your harness? Try a little contact cleaner and firmly seat the plug. Double check to make sure no wires/connectors are being pushed out when you plug it in.

Poor connections in the cluster can also make the ALT light glow. There's a current trace shared by some of the idiot lights and maybe the fuel indicator.

Have you tried jiggling the key to see if some position allows everything to work? I had an ignition lock assembly that wouldn't return the key from "START" to "RUN", had to move it manually. If it wasn't in the detent correctly the heater fan wouldn't work. Don't really know if anything else was affected.

At any rate, sounds like your ignition lock is starting to go. You should replace it before it locks the ignition permanently.

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mjk

'84 300SD 119KMi (Liesl der Diesel)
'84 300D 326KMi when the oil left (former parts car)
'82 300SD 253KMi (new parts car)

UPDATE:

Replaced the ignition switch . . . all is well. Fixed all the problems.

I don't know the brand of this one (came with the vehicle when I purchased it) so I'll be ordering one from Mercedes on Tuesday.

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1982 240
460,000 miles total
140,000 on Rebuild

My car just started having this same problem! Thanks!

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles