Dokta:
Even when I put the black to the outer ring I did not get 1 volt - maybe .003 volt or so. Anyway, I'll need to find a module.
Thanks very much for your help.
Cary.

For anyone who is interested, I just replaced the ignition control module and the car runs normal. I was lucky to find a good used module at a good price. The usual price for a good used one, if available, is about $1200 or so. I also found a manufacturer in Florida who can rebuild this unit and many other ECU's. They charge $975 and provide a one year warranty: Auto and Truck Electronics (ATE), autoecu.com.

ignition module
 

hi carymcooper
on my 1988 300 SE, I am also having problem with crank but no start, and like you I replaced crank position sensor, my crank position sensor wire looked bad and insulation on the end where it goes into crank was oily so I replaced it and the result was no start, I know it is not fuel problem, when I was testing for spark, initially I was getting very weak and not always, now it is not even sparking at all, my question is, was your coil also bad as well as your ignition module?, I am looking around for a good used ignition module, any help on a location for a used module is appreciated.
thanks

First let me correct something I posted yesterday: Auto Trucks Electronics can be found at autoecu.com or 800-257-3359. Sorry for the wrong info.
Second: I did replace the coil during my "trouble-shooting" stage because it was nasty looking/old and not too expensive - a cheap fix if it worked, but it did not solve the problem. I would think you should not have a problem finding a module for a 1988 300 SE as that is a 103 motor? and many more of them were made than the 300CE as well as the module being much more simple and cheaper. I would recommend the following contacts: AutoTruckElectronics(see above)to check on a rebuild; SilverStarRecycling.com;EuropeanConnection(800-395-8636);EVERYBENZ@aol.com;MercedesDismantlers.com;MercedesPartsUsed.com;ActionSalvage.com;PotomacGerma n(pgauto.com);Parts-ToGo.com;QualityAutoParts (qaparts.com).
Cary

Help!
 

Cary,

90 300CE, W124 Coupe, 104.980 motor

I seem to have a similar problem and wanted your advise if possibe. I read thru the thread and have a few questions.

Pulled in the drive way and it hasn't started since. Turns over, no problem. I assumed it was the coil, an Ohm test showed open, both coils. Replaced it. Still nada, wont start. Replaced the plugs, cap, rotor, still nada.

I have 12v, goin into the coil, both sides, same as you did, and only 12v comming out of the coil. No pulse, just 12 constant. Shouldnt this be a much higher voltage?
From the camshaft pos sensor, I have .5v ac when cranking...no good?
Continuity from the Coil to the module, and ground, same as the pins you tested.
Is the Crank sensor easy to replace? I cant seem to find the end by the flywheel.

Any recomendations on what to do next, aside from purchase a new ECU and hope that solves it?

Thanks in advance for any input you can provide.