Hi All,

First off some background on the vehicle. It is a 1989 300e with 83,000 miles. I am the second owner and the battery (Intersate) was last replaced 2 years ago.

I reside in Chicago, Il and I was driving home in a snow storm this evening with temps in the 20's. Traffic was a mess and was crawling along at speeds of up to 10mph stop and go, when my trouble began. The streets were unplowed and the car was losing traction as I could hear the ABS as I came to stops. I had the rear defroster on along with the heat on..headlights etc. After about 1 hour of this my dash gauges start to go dim and I could hear the heater blower motor slow down. About 2 minutes before my gauges went dim I noticed that the little yellow light on the rear defroster rocker switch began to flash on/off. I quickly turned the heater off as I slowed down but it was too late...she died right there on the inside lane of a 4 lane road :( Tried to start her up and nothing not even a click. Opened my door to get out and I see that the dome light in front of the sun-roof is flashing on and off almost like a morse code..lol 2 quick flashes and then a slow one....DOH! I was able to flag down a pickup driver who in turn for the crisp $20 dollar bill I had would give me a jump. She started right up with the jump like nothing was ever wrong. So i'm looking for the support of the Mercedesshop members to help me isolate the cause of this frustration this evening. I thought for sure if the alternator was bad I would have drained the battery and the jump wouldn't have kickstarted her heart. Driving the 3 miles home after that she alomost died once again about a block from the original location. After that I just shifted to neutral at stops to keep the RPM's up there. Keep in mind that in all of this i barely got over 20mph as I was in the heart of rush hour and snowing like crazy. What could be wrong here? And why were the lights on the dome and defroster switch flashing? I got home and torqued the bolts for the battery terminals and they were tight. The car started right up without trouble but as soon as I turned on the accessories and shifted into gear the lights would start flashing again.

Sorry for the long post..any replys would be greatly appreciated,

Regards,

Sam

Two things, your battery is or has failed, or your alternator can't handle the load your asking for. Have the battery load tested and get the charging system evaluated as well. Most likely alternator can't keep up, especially if it's the original and the brushes have never been changed. Get it looked at ASAP, this will not go away, especially with the cold weather in your face, so to speak..

M Benz came to the same conclusion and on the 1990 & later cars they installed higher output alternators. This will bolt to your engine but you need the wiring harness as well. The harness lists for $55. & the higher output alternator isn't but a couple more $$$ than orig.

Thanks for the replies...I going to check the battery and will definately look into the HO alternator that came with the 90 and up cars.

Jet,
When the alternators start to fail, they will work at random, thus passing charging system checks at times. I would have the battery checked with a digital tester. If it checks OK, I would have the alternator replaced with the HO one as Doc said.

It sounds to me like your alternator and/or battery are right on the edge. Check out the battery and get a new alternator or replace the brushes in the existing one (easy fix).

The same thing happened to me. The tape player was slow for a couple of days, then the ABS light came on, then after a slow drive through traffic with the AC on, no start.

Brushes fixed the problem.