The firewall thread was for a later model with dual firewalls..

..but , now that you have jumper to x27, you have to test battery voltage..if low, then the starter solonoid will not pull in. The x27 test is from x27 downstream to starter , but it does not test the starter circuit for low V, it test power to x27.
Don't assume the starter bad until you verify Bat V
An easy test is to put the headlamps ON and watch that they do not dim out when you jumper to x27..if YES, then you have low voltage and should charge the battery before buying a starter [ and check the connections at starter, specially the main cable..

You can also put a test lamp on x27 and try the key to verify upstream.....you can see that on the schematic.
X27 is a comvienent test point we use to seperate a fault from the cabin or the engine compartment..you then know upstream/downstream circuit fault direction/isolation..a good central test point in the start circuit.

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A Dalton

good point. Here are some observations that I have:
1. Batt voltage at NO load is 12.4V
2. When ignition is at "Start" position and X27 connected, dash warning lights dims and stays dim even after ignition switch returns to "RUN" position. It takes a while before dash warning lights return to normal illumination. Starter does not spin.
3. The same is observed when X27 is disconnected. It looks like other components are drawing current via X26 even if the starter is disconnected at X27. Does this symptom suggest another possible problem?

I think it may help diagnose the batt if I measure the voltage ( with load) accross the batt term when doing #2 and #3. what do you think?

I think you have low voltage battery..[ or bad starter]
Charge it overnight ..or , simply jumper the car with another known good battery and see if starter kicks in.
You are almost there........and you did good reading the schematic series chain..

I would also take a battery jumper cable set and just use the neg cable...hook one end to bat neg and the other to engine ground..that will eliminate any possible Bad Grounds.
If that works, then look at all ground cables [ brown ones ] and the one going from the trans bellhousing to chassis ..the flex one.

A last possible is the starter brushes are so far worn that the starter is drawing high amps and just won't turn b/c of the wear..you will know that when you jumper from a good battery. Sometimes a good smack on the started will get the worn brush to seat, but it will be temporary and will definately need a starter........just don't want you to buy one until you know you need one.............

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A Dalton

you are correct. it was a bad battery. I had to call a roadside assistance as i wanted to get the car out of the driveway so I can get my second car out of the garage,a 66 mustang conv. The tow guy thought at first too that it was a starter problem, but I asked him to try and jump it anyway. 3 tries on the ignition switch and it started up. I took the battery to Kragen where I originally bought it, and it tested bad. It is an autolite. I got 50% off for warranty. Thank you for the pointers. very helpful indeed. I have another problem that I will start a new thread. I have been having this hard start problem after I rebuild the engine. I will soon have some time to focus on it. hopefully you will be available to help....

Very Good.................

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A Dalton

i'm hoping to get a little help with my e320. excuse me if i'm interupting a thread if i am. i'm new here.

94 e320: alarm will not disengage so i'm unable to start the car. the car was left out with the top down recently during an unexpected rain. i figure that may have something to do with the problem.

any help would be appreciated.

I just wanted to take the time to say thank you Dalton. I experienced a no start/no crank situation with my 1995 mercedes E320 wagon, and I spent quite a bit of time trying to track down diagnostic information & wiring diagrams without much luck. I found a few posts that referenced a few things here or there, but none of them took the time to describe the circuit in detail. Your posts made the entire process perfectly clear. I now understand the path of the circuit from the battery all the way to the starter; the location and appearance of the ignition, K38, X49, K27, and starter sections of the circuit; how to properly jumper these locations if it is necessary to bypass them; and the really handy K27 "emergency" start trick. With your post I can finally diagnose & fix my car...that is once it stops being a pain in the butt by deciding to work again. I know that it will break again sometime soon, and until I can afford a new digital multimeter I don't have the ability to test beyond On/Off with my test light. I also wanted to tell you...not sure how to put this, but you have great patience with dealing with others. I know that electronics can be a pain to deal with, but it definitely helps to follow the procedure...and the path of the circuit...and I suppose to understand basic circuitry. Thank you again very much!

Most of what you need to fix this problem is probably contained in these posts. I would start by disconnecting and reconnecting the battery. Then I would check fuses 5, 11, 12, 13, and B with a multimeter or test light. Be sure to test at the connectors as opposed to the fuse itself, so you can be sure that not only is the fuse good but that it also is getting a good connection. Hopefully, the solution to your problem will be found somewhere in there. Otherwise, you may have a problem with the actual ATA unit itself. I believe there is a way to bypass it, but I'm not 100% on that. You could also obviously replace it if it is bad, but that's a choice you have to make based on how much money you're willing to spend for a given level of functionality. Since this post was made back in 2008 I'm going to assume that you no longer need this response, but maybe someone else will. I find that usually disconnecting the battery resets the alarm.

**Edit**

I'm pretty sure that the fix for bypassing the ATA is simply jumpering the K38 relay. You can find the correct pins and wire colors earlier in this thread.

You're Welcome .

A Dalton
BenzTechs

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A Dalton

Just wanted to add that the description for fuse 5 does indeed tell you that it's for a bunch of random things unrelated to the starter circuit, but they LIE! It is definitely a key point in the starter circuit despite what they say on the little card on the fuse panel

I can also verify that on mine I have the same colors for the wires

What would you suggest for jumpering these terminals? A piece of 18 or 20 gauge wire or something like that bent in a U shape? If I didn't happen to have any wire lying around do you think an upholstery staple bent in half would work? I know it sounds kind of...well...iffy, but I can't really think of a reason why it shouldn't work off the top of my head. What do you think?

I'm just going to go ahead and slap myself for suggesting using a staple. I mean I suppose it could work in an emergency, but then again in an emergency you might as well just jumper the X27 connector to the + terminal. I discovered that anything under a foot of wire at HD is free, and I needed to pick up some solder, flux, and a few other things for another project anyways. I got about a foot of wire that contained 5 strands of 20 gauge solid core insulated wire. I pulled the outer sheath off; stripped the insulation off one of the wires; wrapped it in a figure 8 pattern around the 2 prongs; and then finished it up with a bit of solder just to ensure a solid permanent connection & to help keep it in place. Congratulations to me for finally getting a hand on soldering. I don't know why, but I've always been HORRIBLE at soldering anything. For probably the first year of soldering my technique involved touching the tip to the solder, and dripping it onto what I was soldering. In case you don't know...that is NOT how you solder, and that will create what we call a cold soldered joint which is extremely weak. Nobody told me, and back then we didn't have youtube and stuff like that for me to learn from easily. Again, in case you don't know... the proper way to solder something is to touch the tip to what you are soldering until it gets hot enough to melt the solder. You need the wire or post or whatever you are soldering to heat up to the same temperature as the solder in order to create a strong joint. I guess back then that I thought this would damage what I was working on or something like that. I don't know, maybe I just thought it was easier. Anyways, I put the modified relay into the car, and it cranks and starts strongly each and every time. Oh, and for the record it is the silver relay not the blue one...at least in my 1995 w124 wagon. It's the one furthest to the left. I believe the other one has to do with the dash itself because when I jumpered that one earlier I blew fuse 5 and my tach went out. Replacing fuse 5 brought my tach back.

What a great troubleshooting thread here! I have had low battery issues which cause no start..and also the immobilizer relay up behind the gas guage failing...I would need to bank on the dash on the left side and then it would click and start right up and I just replaced the relay for $20 including shipping and its dead reliable now..

These cars work so great when the issue is identified and resolved but are so complex as to be confusing if you are missing a little information..AD and Rick 76 and others are a wealth of assistance and hopefully we can pass on the good information..(94 and 95 E320)