86' 300E electrical problem, hesitation, ABS light on
09-12-2008, 10:58 AM
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1986 300E
86' 300E electrical problem, hesitation, ABS light on
Kind of an odd problem. The car runs fine most of the time. Once in a while the Antilock brakes light comes on and the car suddenly won't idle, and runs poorly. Anyone have any similar problems? Also, does anyone know where I can find a wiring diagram for this car that has the ABS and engine wiring in it? I have a feeling there's a short somewhere.
09-12-2008, 06:48 PM
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90 300E, 03 E55 Black designo, 06 IWC CLS55
I would very confidently tell you that if it is intermittent, ABS light and rough idle, that it is your OVP or overvoltage protection relay. Behind the battery there is a plastic cover that you must slide down and forwards then upwards to remove about 20 cm in length. Behind it you will find the relay with a a fuse or two on top 10A red fuse(s). Costs about 120 USD from dealer or about 75 USD from autohausaz.com, who I buy all my parts from for my 300E while in California. Free postage over 50 USD purchase. I live in London now, but while i was there I was so fortunate to be able to order all my OEM parts from them and not the dealer (Encino Mercedes) who was such a bloody rip off! I have no affiliations with them but I was so happy with their service and it never took more than 3 business days to be received at my house in LA (coming from Arizona, not too far).
So many 300e/260e owners have changed it over their period of ownership, always an expected change, viewed more as a 'wear item' that should be changed after a particular time/mileage period to avoid problems.
Good luck,
So many 300e/260e owners have changed it over their period of ownership, always an expected change, viewed more as a 'wear item' that should be changed after a particular time/mileage period to avoid problems.
Good luck,
09-12-2008, 10:56 PM
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95' AMG SeeThreeSix
I'll second that! Sound to me like an OVP relay issue. My 1986 sedan had the same hesitant operation when the OVP went bad. Sometimes you can repair it using some solder and soldering iron, look for melted contacts and or cold solder joints.
09-15-2008, 03:30 PM
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1986 300E
Yeah, that was it. The relay had cracked solder joints and the fuse that plugged into the top was all corroded. Resoldered and cleaned it up/replaced the fuse and the car runs 100% better. Now hopefully I can get this thing on the road again. Thanks for the tip, it would have taken me ages to find that going in blind.
