Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 10 of 12 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
Electrical System. Review the 12 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
Suspension. Review the 1 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
0 crash reports0 fire reports0 injury reports
What owners actually said
12 reports
130,000 miles · Jan 17, 2010
Electrical System
MERCEDES-BENZ ENGINE WIRING HARNESS DEFECT CONCERNING THE CHRONIC ENGINE COMPARTMENT WIRING HARNESS FAILURE SUFFERED BY (AT LEAST) 1992 THROUGH 1995 MERCEDES BENZ AUTOMOBILES. I AM OUTRAGED AT MERCEDES-BENZ' REFUSAL TO TAKE RESPONSIBILITY FOR THIS DESIGN DEFECT. I DO NOT UNDERSTAND WHY NHTSA HAS NOT INVESTIGATED THIS DANGER…
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MERCEDES-BENZ ENGINE WIRING HARNESS DEFECT CONCERNING THE CHRONIC ENGINE COMPARTMENT WIRING HARNESS FAILURE SUFFERED BY (AT LEAST) 1992 THROUGH 1995 MERCEDES BENZ AUTOMOBILES. I AM OUTRAGED AT MERCEDES-BENZ' REFUSAL TO TAKE RESPONSIBILITY FOR THIS DESIGN DEFECT. I DO NOT UNDERSTAND WHY NHTSA HAS NOT INVESTIGATED THIS DANGEROUS FAULT, ESPECIALLY WITH THE HUGE NUMBER OF COMPLAINTS. ONE STARTS TO WONDER IF NHTSA HAS BEEN PAID TO LOOK THE OTHER WAY. *TR
NHTSA ODI #10300109
130,000 miles · Jan 17, 2010
Electrical System
INSTRUMENT CLUSTER DOSE NOT FULLY WORK. THE TEMP GAUGE IS THE ONLY ONE THAT WORKS ALL THE TIME. THE REST OF THE TIME, THE CLUSTER MAY WORK FOR A TIME THEM STOP FUNCTIONING ALTOGETHER. *TR
NHTSA ODI #10300045
75,000 miles · Jun 28, 2009
Electrical SystemSuspension
MERCEDES DEALER REPAIR SHOP REPORTED TO ME THAT THE WIRING HARNESS IS MADE OF BIODEGRADABLE MATERIAL AND HAD TO BE REPLACED. THE FAULTY HARNESS CAUSED SEVERAL PROBLEMS WITH ENGINE, INCLUDING ACCELERATION. I HAD THE PART REPLACED IN 2000 AND DO NOT HAVE THE ORIGINAL. BOTH CATALYTIC CONVERTERS WENT BAD AT 100,000 MILES FOR NO R…
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MERCEDES DEALER REPAIR SHOP REPORTED TO ME THAT THE WIRING HARNESS IS MADE OF BIODEGRADABLE MATERIAL AND HAD TO BE REPLACED. THE FAULTY HARNESS CAUSED SEVERAL PROBLEMS WITH ENGINE, INCLUDING ACCELERATION. I HAD THE PART REPLACED IN 2000 AND DO NOT HAVE THE ORIGINAL. BOTH CATALYTIC CONVERTERS WENT BAD AT 100,000 MILES FOR NO REASON. MAKES CAR RUN ROUGH, ESPECIALLY ON ACCELERATION. MERCEDES MECHANIC STATES IT IS A FIRE HAZARD, AND COST TO REPLACE EXCEEDS $2200. SHOULD HAVE BEEN INCLUDED IN RECALL FOR LATER MODELS. SUSPENSION IS BAD IN THE REAR EVEN AFTER PARTS HAVE BEEN REPLACED. *TR
NHTSA ODI #10275126
Mileage unknown · Apr 25, 2009
Electrical System
I PURCHASED A CLASSIC 1994 S320 FROM THE ORIGINAL OWNER AND AFTER FINDING OUT I HAD A OIL LEAK I HAD TO HAVE THE ENGINE GASKET REPLACED THE MECHANIC SAID THAT THIS WAS A PROBLEM WITH THIS MODEL ALSO I'VE HAD TO HAVE THE WIRE HARNESS REPLACED BE CAUSE I WAS TOLD THAT THE HARNESS WAS MADE FROM BIODEGRADABLE MATERIALS THIS WAS A PR…
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I PURCHASED A CLASSIC 1994 S320 FROM THE ORIGINAL OWNER AND AFTER FINDING OUT I HAD A OIL LEAK I HAD TO HAVE THE ENGINE GASKET REPLACED THE MECHANIC SAID THAT THIS WAS A PROBLEM WITH THIS MODEL ALSO I'VE HAD TO HAVE THE WIRE HARNESS REPLACED BE CAUSE I WAS TOLD THAT THE HARNESS WAS MADE FROM BIODEGRADABLE MATERIALS THIS WAS A PROBLEM THAT COULD HAVE CAUSED A POSSIBLE ENGINE FIRE I THINK THIS WAS A MAJOR DEFECT AND SHOULD HAVE BEEN ADDRESSED YEARS AGO MY ENGINE#003388 IF YOU BUY NEW OR OLD MERCEDES-BENZ IS THE BEST CAR IN THE WORLD AND THE COMPANY SHOULD ADDRESS ALL PROBLEMS. *TR
NHTSA ODI #10266725
Mileage unknown · Nov 16, 2008
Electrical System
I OWN A 1994 MERCEDES S600 WITH V12 ENGINE. THE WIRING HARNESS ON THE ENGINE HAS DETERIORATED TO THE POINT THAT IT IS A HAZARD TO DRIVE ON THE HIGHWAY NOT ONLY FOR THE SAFETY OF MY FAMILY BUT TO THE GENERAL PUBLIC, IT IS A FIRE READY TO BURN AT ANY MOMENT, I UNDERSTAND THAT MERCEDES WILL NOT ADMIT THE PROBLEM AND HAS REFUSED TO…
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I OWN A 1994 MERCEDES S600 WITH V12 ENGINE. THE WIRING HARNESS ON THE ENGINE HAS DETERIORATED TO THE POINT THAT IT IS A HAZARD TO DRIVE ON THE HIGHWAY NOT ONLY FOR THE SAFETY OF MY FAMILY BUT TO THE GENERAL PUBLIC, IT IS A FIRE READY TO BURN AT ANY MOMENT, I UNDERSTAND THAT MERCEDES WILL NOT ADMIT THE PROBLEM AND HAS REFUSED TO CORRECT EVEN THOUGH OVER 500 COMPLAINTS HAVE BEEN FILED. THIS IS A COMMON PROBLEM ON '94 THROUGH '96 S MODELS. *TR
NHTSA ODI #10248926
96,700 miles · Jul 31, 2008
Electrical System
TWO REPUTABLE INDEPENDENT MERCEDES MECHANICS INFORMED ME THAT THE ENGINE WIRING HARNESS INSULATION IN MY 1994 S420 IS DECAYING WHICH MAY HAVE CAUSED MY LH CONTROL UNIT, AND M.A.F TO FAIL TO MALFUNCTION AND THIS PROBLEM IS PREVALENT IN MERCEDES VEHICLES MADE FROM 1991-1996. THERE SHOULD BE A RECALL ISSUED FOR THIS PART BEFORE MO…
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TWO REPUTABLE INDEPENDENT MERCEDES MECHANICS INFORMED ME THAT THE ENGINE WIRING HARNESS INSULATION IN MY 1994 S420 IS DECAYING WHICH MAY HAVE CAUSED MY LH CONTROL UNIT, AND M.A.F TO FAIL TO MALFUNCTION AND THIS PROBLEM IS PREVALENT IN MERCEDES VEHICLES MADE FROM 1991-1996. THERE SHOULD BE A RECALL ISSUED FOR THIS PART BEFORE MORE SERIOUS EVENTS OCCUR DUE TO THE FLAW IN MERCEDES MANUFACTURING PROCESS FROM 1991-1996 . *AK *TR
NHTSA ODI #10236564
359,000 miles · Jul 29, 2008
Electrical System
ENGINE WIRE HARNESS IS CORRODED CAUSING SEVERE MECHANICAL PROBLEMS. *TR
NHTSA ODI #10236311
155,000 miles · Jul 20, 2008
Electrical System
I HAVE A 1994 MERCEDES BENZ S600 THE CAR IS IN GOOD SHAPE BUT IT START STALLING ONCE I WAS PULLING OUT IN TRAFFIC I WAS ALMOST A GONER AND THE PROBLEM KEPT OCCURRING AND THEN I TOOK IT IN TO A MB MECHANIC TO FIND OUT WHAT'S GOING ON AND IT HAD MANY TROUBLE CODES BUT THE PROBLEM WAS WITH THE WIRE HARNESS IT WAS COMING A PART AND …
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I HAVE A 1994 MERCEDES BENZ S600 THE CAR IS IN GOOD SHAPE BUT IT START STALLING ONCE I WAS PULLING OUT IN TRAFFIC I WAS ALMOST A GONER AND THE PROBLEM KEPT OCCURRING AND THEN I TOOK IT IN TO A MB MECHANIC TO FIND OUT WHAT'S GOING ON AND IT HAD MANY TROUBLE CODES BUT THE PROBLEM WAS WITH THE WIRE HARNESS IT WAS COMING A PART AND CAUSING SHORTS IN FUEL INJECTION SYSTEM THIS SHOULD HAVE BEEN A RECALL WHEN I FOUND OUT THE NUMBER OF PEOPLE WITH THE SAME PROBLEM. *TR
NHTSA ODI #10235044
95,000 miles · Nov 15, 2007
Electrical System
TL*THE CONTACT OWNS A 1994 MERCEDES BENZ S500. THE CONTACT STATED THAT THE ENGINE WIRING HARNESS IS DECAYING AND THE WIRES ARE SHORTING. AS A RESULT, THE ASR IS ENGAGED, WHICH REMOVES THE THROTTLE CONTROL FROM THE VEHICLE. WHILE DRIVING APPROXIMATELY 70 MPH, THE ASR LIGHT ILLUMINATED AND THE VEHICLE DECELERATED ON ITS OWN. T…
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TL*THE CONTACT OWNS A 1994 MERCEDES BENZ S500. THE CONTACT STATED THAT THE ENGINE WIRING HARNESS IS DECAYING AND THE WIRES ARE SHORTING. AS A RESULT, THE ASR IS ENGAGED, WHICH REMOVES THE THROTTLE CONTROL FROM THE VEHICLE. WHILE DRIVING APPROXIMATELY 70 MPH, THE ASR LIGHT ILLUMINATED AND THE VEHICLE DECELERATED ON ITS OWN. THE FAILURE ALMOST CAUSED THE CONTACT TO BE REAR ENDED BY ANOTHER VEHICLE. THE VEHICLE WAS TAKEN TO THE SHOP A FEW TIMES, BUT THE CAUSE OF THE FAILURE COULD NOT BE DETERMINED. THE FAILURE MILEAGE WAS 95,000 AND CURRENT MILEAGE WAS 125,000. UPDATED 12/12/2007 *BF UPDATED 12/12/07 *TR
NHTSA ODI #10209018
53,613 miles · Nov 12, 2007
Electrical System
ENGINE RUNS ERRATIC, VARIOUS ELECTRICAL MALFUNCTIONS INCLUDING TEMP GAUGE, SRS, FUEL INJECTION. CAR SOMETIMES WILL NOT START AND OTHERS STARTS IMMEDIATELY. REPAIR SHOP SAYS ENGINE WIRING HARNESS NEEDS REPLACING. *TR
NHTSA ODI #10208707
Official recalls
0
No recalls in this snapshot.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0
No exact-year investigations in this snapshot.
1994 Mercedes Benz S Class Problems, Complaints & Recalls | Skip That Year