HELP --Online wiring diagram for a 240D?

Hello Everyone,

I'm stuck with a car that has neither brake lights nor blinkers. Only 6 fuses have power. I need to get at a wiring diagram to see the wiring between the ignition key, the main lighting switch and the fuse box. Is there one on line somewhere? I had hundreds of hits in my searches but they always end up with nothing.

What about the possibility of a temporary connection - a short one between a powered fuse and the fuse that controls the faulty lighting? That would allow me to get to a manual, with the wiring diagram. Possible burn out of components as a result?

Help appreciated.

TIA

MR

Reply to
Madra Rua
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Is the ignition switch good? They can malfunction.

Just a thought.

Reply to
Gene

Thanks Gene for your effort.

I finally was able to get at my manual and believe that it IS the ignition switch.

I scanned the wiring diagram and spent 30 mins setting it up on a web site:

.

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Page 1 is the part of diagram with the fusebox and the ignition- and light-switches.

There are two wires from the ignition switch to the fuses - one (red green) goes to fuses 4 and 6 (coupled) and the other (red black) goes to point 15 in the fuse box, feeding fuses 8 through 14. Fuses 8 through 14 have no power which suggests that the ingnition switch is not providing any "juice."

Hopefully thaat web site will be able to spare someone my recent woes.

Thanks again,

MR

Reply to
Madra Rua

More info. Just checked with local MBZ dealer about the ignition switch. It has 3 parts:

1 Ignition tumbler part - $111 2 Electrical portion - $31 3 Lock mechanism - $207

Not exactly cheap.

I'm hoping all I need is the electrical portion.

Comments appreciated.

MR

Reply to
Madra Rua

If it's an old car with a lot of turns on the key, replacing the tumbler is a good idea also.

marty

Reply to
Martin Joseph

I don't recall tumbler being so high priced... but is adviseble to be changed if you still have original tumbler. Yes, you basically only need the ignition switch (electrical portion). The locking mechanism includes the electrical portion.

Reply to
Tiger

Thanks Tiger and Martin. Much apprerciated :-)

The car has only 85K miles on it and, although I could expect an electrical part to go, I think mechanical parts should be more durable. If the tumbler part cost about $30, I would replace it but, at the price quoted, I'll wait.

Now the problem is to replace the electrical part. My three big fat MBZ manuals are broken down into an engine part, a body and electrical part and a body part. I can't find any mention of the ignition switch. I also noticed that the wiring diagram doesn't include a battery!!! I have a Haynes manual that supposedly covers the E300 series but it doesn't mention an ignition switch either.

I had an idea today to short out, on the ignition switch, the circuit that has no feed from the battery. This would get the car going again until I had the electrical part. However, I need to get the assembly out and it's firmly fixed. It is stuck in its socket, which is a short stub of pipe that sticks out of the steering column and has a clamp around it to tighten the assembly in place. I have the bolt very loose on the clamp and the assembly will move out of place only about 1/8" and then hits a hard stop. Besides that problem, I'm not sure it can come out without removing the dash. Anyone had experience of removing the assembly?

TIA

MR

Reply to
Madra Rua

It is in the chassis manual along with steering. To get the wiring harness off, you need to have the key in position 1. To pull the entire assembly out, you need to press in one metal tab... it is faced toward the rear of the car (front seat direction)... easy way is to insert a straight stiff coat hanger wire through the dash and guide it with your finger and push it in.... then twist the entire assembly 90 degree and you can pull it out completely.

Reply to
Tiger

Hold that thought!

The electrical portion of the switch is only attached by three screws and you may not have to take the entire steering lock assembly out to get to the electrical part. It should be a matter of unplugging the wiring connector (the cylindrical plastic part with all of the wires going into it) by pulling it strait off (forward) of the electrical portion of the switch. Then you locate the 3 screws that hold the electrics to the lock mechanism, loosen them and the electrical portion will come off. Reverse and your back together. There will be some on your head, under dash work but no pain, no gain.

Gene

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Reply to
Gene

It is a real pain trying to put those three screws back in with the unit in position... believe me.. I did it on two cars... not fun at all... much easier with the lock out.

Reply to
Tiger

Thanks again Gene and Tiger.

Had a look today with an inspection lamp at the switch assembly. I had loosened the U clamp and the assembly moved out of place, away from the steering column, by about 1/4", which gives me peeping room on the steering column side. There is a channel machined into the casting there and what looks like a plastic cable connector pushed into it. I can't see any more there, apart from solid casting. I was able to get my hand around most of the unit and couldn't feel anything that could be a tab.There is no tab visible between the black cylinder and the edge of the hole in the dash. I was able to push in a strong hanger wire and even a slender screwdriver there, while rotating the black cylinder - but nothing gives. I tried the same thing with the key in place but that didn't do any better.

Underneath I can see only a single small screw - about 3mm. There is another one keeping the double tube unit (vacuum?) attached but it would be very difficult to remove. I also noticed a small hole in the casting and when I put a wire in there I couldn't turn the key, which suggests it might be what is used to push out broken keys?

Thanks again for your patience

MR

Reply to
Madra Rua

That tab is nearby that clamp you loosened... and your key must be in position one to push that tab in.

Reply to
Tiger

Thanks again Tiger,

I bought the electrical part of the ignition switch and I now have access to all my manuals. However, I cannot locate the section where the ignition switch is described. I have the engine manual and the chassis manuals parts

1 and 2. There is no index in any of them and the contents page for each manual is truly abysmal - doesn't even cover a small fraction of what's there. Which section is the steering wheel / ignition switch in? Thanks

When I was buying the part, I was told that there are two types of assembly and I would have to know my chassis number to decide which was the right one. Mine is wdb1231231a124698 but I think only the 123.123 numbers were used. Maybe there is a tab on yours and not on mine. They gave me a copy of the assembly drawing but it shows no tab - just the small electrical connection on the assembly unit between the black cylinder and the steering unit. .

Went back to the car again and I am confident there is no tab on my asssembly. I recognized the electrical part of the switch under the electrical connector but it's very hard to get at. The connector is wedged against a plastic duct (about 3" diameter) and, even with that connector out, it would be very difficult to get at the screws as Gene suggested.

There are 3 marks on the switch around the black cylinder where the key rotates, one near where the key is when first inserted and another further around just about where the ignition is turned on, I believe, and a third one around further where the car starts. I tried the key at various positions, then pushed a screwdriver into the area you suggested - probing all around, while trying to rotate the black part of the assembly - tried both directions - wouldn't budge. There is also a small hole on the metal cylinder that the key fits into. It is near the outer edge - at the inner diameter of the black plastic part. Know what it is for? I had a wire of the right diameter and I pushed it in there while rotating but it didn't seem to do anything.

Thanks again for all the patience.

MR

Reply to
Madra Rua

First of all. you are getting all mized up on what I am saying. This steering lock/ignition is a very simple device. It is located in your chassis manual... look by steering components/ instrument cluster. It is there... because I have seen them in two of my chassis manual of two different models.

Like I said, it is much easier if you just take the whole ignition lock assembly out of the car. To get this out...

  1. Turn ignition key to position 1... this release the steering lock that prevents the steering wheel from turning.

  1. Loosen that clamp nearby the steering column.

  2. The round tab is located nearby the clamp faced toward the rear end of the car. You cannot visibly see it from underneath the dash. Use your finger to locate that tab... Use high power flashlight to assist in searching for it if you try to look for it via front of the dash. It is there.

  1. Once you located that tab, push it in with a stiff wire and then rotate the entire assembly so the tab does not engage again.... then slide out the unit.

If you do not want to remove the entire assembly, then you will have to try to work around the rear using miniature screwdriver to remove the screws of that ignition switch. A real pain. Again, your key must be in position 1 so you can remove the wiring harness.

Reply to
Tiger

Huge thanks again Tiger,

Finally, I have all my manuals and found the section on the steering column. From now on, where the manuals go, I go ;-)

The manual claims that the way to go about replacing the electrical part is to remove the instrument cluster first.

You seem to have a slightly older version where the wire is pushed in on the outside of the black cylinder.

For mine it seems that the wire is pushed in the hole, that I mentioned in my last post, between the key cylinder and the surrounding black plastic cylinder (the manual calls it the cap) is what releases the unit, with the key at position 1. Numbers are not marked on mine. I don't understand why it is necessary to go through so many steps to replace the electrical part. It shows the instrument cluster removed to give access to the electrical part, which is connected to the rest of the assembly by just three screws, as Gene mentioned. If the key is in place it should align correctly when pushed into place. No?

Will remove the lock as you suggest and then try to take the complete unit out to replace the electrical part.

At long last, hopefully I'll get this job done today. I've never had a problem as long drawn out as this one.

Will report soon

Thanks again.

MR.

Reply to
Madra Rua

Just remember, make sure the position of the key line up with your ignition switch you got... because that key tab inside the lock thing will break easily and that would force you to spend $200 for the new unit. I recall spending $135 for mine at the dealer.

Reply to
Tiger

Thanks for the tip Tiger. $135 ouch! Condolences. Will watch it carefiully. I saw how fragile some of the bits are.

I had no problem getting the lock off - after I found the right size wire - a big paper clip :-) . Then I pushed in the detent down at the steering column. That allowed the assembly to move out some more, but it still needs about 5/8" to come all the way out of the socket and the whole area there is so crowded that I cannot move it any further. I tried to pry off the big cable connector to make some more room but had no success. Seems like I need a knife to start it. It now looks like I will have to remove the instrument cluster first and that in itself is another pain. The cables are so tight I can barely find enough space to get a wrench in behind the cluster unit.

Struggle on ;-)

Thanks again

MR

Reply to
Madra Rua

Some success. I found out why I was having so much trouble with the instrument cluster and the lock. It must have been a Monday morning assembly. Both the oil pressure cable to the cluster and the vacuum tubes to the lock were routed in a roundabout way that made them both tight. I have rerouted so this shouldn't happen again.

I replaced the electrical part but am puzzled by a small difference from the one I removed. Looking into the center of the new one, I see a slot of about

1/4" x 1/2" and in it is a round plastic rod with a slot across most of the width. Thie top of this is the level of the bottom of the pins i.e nothing sticks up. In the old one there is a mason's hammer (a head on each side) like piece of plastic that projects up from the same size slot - 1/4" x 1/2" that the other one has. This "hammer" projected up about 5/8" and fitted into a slot on the cable connector. I tried to remove it to install it in the new one but it is built into the unit.

Looks like light at the end of the tunne :-)

Have an enjoyable weekend,

MR

carefiully.

Reply to
Madra Rua

More progress but a glitch.

I have everything connected to the lock assembly - vacuum tubes and two electrical plugs - but the the unit won't move far enough down towards the steering column. The detent near the steering column is out in its place but the assembly seems to be about 1/8" out too far* - judging from the position of the key cylinder unit in the hole the instrument panel. In that position, I screwed the black cap back on, aligning the necessary bits, and then removed the wire but the key would not move at all. When I was disassembling the assembly, I turned the steering wheel a little to the left (it was one of the instructions) and after reassembly, I turned it back but it didn't help.

  • I pushed in the detent and then pushed the assembly towards the steering wheel but it wouldn't budge.

Still strugglin'

MR

Reply to
Madra Rua

The ignition assembly must be in "unlocked" position to fully insert... turn key into position 1 or else.

Reply to
Tiger

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