Great thread here for Curly and others with OM603 (or any analog engine computers from the 80's and 90's, maybe others).
http://www.peachparts.com/shopforum/diesel-discussion/389414-eds-elr-idle-issues-om603.html BLUF (bottom line up front): There are a handful of capacitors in the computer that die and probably are the source of much woe, and replacing them would be A GOOD IDEA if your OM603 has any idle quality issues or kick-down switch issues. ----------------------------- "There are 5 Electrolytic capacitors on the EDS computer boards. On the 126 the EDS computer is located in the passenger kick compartment and requires no tools to remove. Not sure about the 201 and 124. 4 phillips screws in the lid removes the boards which are clipped together. Looking inside the 2 boards, you can see 2 heatsinks that are clamped to some transistors on one of the boards. You will want to remove the 2 phillips screws holding the OTHER board to the main heatsink/plug assembly. You can then lift it off and pivot backwards on the ribbon cable. There are plastic clips that hold the 2 cards together, they simply unsnap. Once you have the cards opened up like a book, the locations of the capacitors are obvious and the capacitors are clearly marked. On the board you didn't unscrew from the main heatsink/plug assembly, there are 4 capacitors: 100µF @ 50V Radial, 100µF @ 10V Axial, 22µF @ 40V Radial, 7µF @ 63V Radial. The board you unscrewed and pivoted out of the way has a single electrolytic capacitor 22µF @ 16V Axial. The circuit cards are double-sided, so be careful desoldering and resoldering. I used 63V parts for all my replacements. 7µF is also not a standard value, so I substituted a 6.8µF capacitor for it. Out of all of my capacitors, only the 22µF radial was good (I replaced it anyway). The next highest reading I got out of any of mine was .006µF In Germany, they'd refer to that as "kaput". ------------- Max Charleston SC _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
