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Discussion Starter #1 (Edited)
HELP: 1989 300TE wagon stops running after SRS, ABS & Light Failure lights turn on!

1989 300TE Wagon
Automatic transmission
6 month old battery
138,000 miles

Problem: Everything dies after a bunch of idiot lights go on.


The 1989 MB 300TE wagon I just bought stopped running last night while I was waiting in line at a fast food place with the engine idling.

Here is what happened...

- I had just driven the car at freeway speeds (approx 65 mph) for about 20 minutes in cool 62 degree fahrenheit air.

- The headlights and radio were on (a cheap aftermarket radio with no external amp that uses the stock MB speakers).

- Then I was at a fast food place at idle speed slowly creeping forward waiting for my order.

- After about 7 minutes in line the 'Antilock' and the 'SRS' red idiot lights turned on. My MB owners manual says this about the 'Antilock' (ABS) light: "If the charging voltage falls below 10 volts, the indicator lamp comes on and the ABS is switched off. When the voltage is above the value again, the indicator lamp should go out and the ABS will be operational."

- Then about a minute later the radio went off and could not be turned back on but the blue light on the front of the radio stayed on.

- Then about another minute later the 'Exterior light failure indicator' lamp turned on. And the MB owners manual says this about the 'External Light Failure Indicator Lamp': "If this light comes on with the engine running it indicates that an exterior light failure."

- Then the engine died and I had to push the car to the parking lot.

- After spending about 15 minutes eating I proceeded to start the car...and it did start!

- I drove about two minutes and got stuck in a long stop light and then the 'Check Engine' light went on and then everything died so I had to push it into another parking lot where it is now sitting.

- The battery is about 6 months old.

- I just bought the car and the seller said something about how the car was conking out on him - but then he said it didn't seem to do that anymore so I bought it.

- The car ran fine earlier that day with no idiot lights going on while it was still light. Don't know if the headlights were what killed it or not.

- Lastly, the first night I checked out this car (last week), the red battery light was on while the car was idling but it would go out when I accelerated. I described this last point to a mechanic and he said it could be the voltage regulator or the alternator...but this was before all this other stuff happened.

If anyone can tell me what might be going on I would greatly appreciate it. And if you think it is a voltage regulator or an alternator, are both of those easy to replace in that car for someone that is NOT a mechanic but is handy with tools.

Thanks very much.

Steve
 

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Specializing in High End European auto repair
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Sounds like the alternator is not charging.

If I remember correctly, on that model its on the left hand side as you're looking at the engine...down under the airpump. Not to tuff a job.
 

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Discussion Starter #3
Thanks for your reply. :)

I am far from being a mechanic, so of course you would know better than me, but what makes you think its the alternator instead of the voltage regulator?

Also, can I buy aftermarket voltage regulators and alternators or do I have to buy original MB manufactured parts from the MB dealer?

Thanks
Steve


Sounds like the alternator is not charging.

If I remember correctly, on that model its on the left hand side as you're looking at the engine...down under the airpump. Not to tuff a job.
 

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1989 Mercedes-Benz 300E
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23 Posts
Could be Alternator get a test free at AutoZone. But OVP relay is common for that ABS light and it will cause your car to stall so dont rule that out. Cheap part. But get the charging test first.
 

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2001 E55 Estate
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Your alternator should be charging at 13.9 to 14.2 volts. Make sure battery terminals are clean and tight. Also check your drive belt and belt tensioner.
You might want to check your overvoltage protection relay fuses as well. If they are not blown check the production date on the side, I like to update the OVP relay(Fig 3) every 4-5 years.

 

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In my '88 300E the battery light never goes on yet I have gone through three alternators in the time I have had the car. Each time, the ABS and SRS lights have come on shortly before the inevitable total shut down. So I would agree that it looks like your alternator is not outputing the correct voltage and/or amperage. This could be a simple regulator change (two screws hold it in on the back of the alternator)
 

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2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
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Regulators stop overcharging, not undercharging.

Only way to figure out what is going on is to test the battery with a DMM.

A) Car off
B) Car on idling
C) Car at 2500rpm
 

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Discussion Starter #8
You said: "this could be a simple regulator change (two screws hold it in the back of the alternator)."

Is the "regulator" you speak of, the voltage regulator?

Thanks
Steve


In my '88 300E the battery light never goes on yet I have gone through three alternators in the time I have had the car. Each time, the ABS and SRS lights have come on shortly before the inevitable total shut down. So I would agree that it looks like your alternator is not outputing the correct voltage and/or amperage. This could be a simple regulator change (two screws hold it in on the back of the alternator)
 

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1991 300D 116,000m
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Regulators have brushes that wear, when they get down to a 1/4" it's time for a new one. Two screws on the back of the alternator. But I wouldn't discount the OVP either
 

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1989 Mercedes-Benz 300E
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Have your batt and alt. tested. Should be free at most places. If things are to spec. Replace the voltage regulator and over voltage protection relay as these are common issues and the newer parts are revised (cheap fix, and considered a tune up if original). Wouldn't be surprised if it solved most your issues?
 

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1989 300TE Wagon
Automatic transmission
6 month old battery
138,000 miles

Problem: Everything dies after a bunch of idiot lights go on.


The 1989 MB 300TE wagon I just bought stopped running last night while I was waiting in line at a fast food place with the engine idling.

Here is what happened...

- I had just driven the car at freeway speeds (approx 65 mph) for about 20 minutes in cool 62 degree fahrenheit air.

- The headlights and radio were on (a cheap aftermarket radio with no external amp that uses the stock MB speakers).

- Then I was at a fast food place at idle speed slowly creeping forward waiting for my order.

- After about 7 minutes in line the 'Antilock' and the 'SRS' red idiot lights turned on. My MB owners manual says this about the 'Antilock' (ABS) light: "If the charging voltage falls below 10 volts, the indicator lamp comes on and the ABS is switched off. When the voltage is above the value again, the indicator lamp should go out and the ABS will be operational."

- Then about a minute later the radio went off and could not be turned back on but the blue light on the front of the radio stayed on.

- Then about another minute later the 'Exterior light failure indicator' lamp turned on. And the MB owners manual says this about the 'External Light Failure Indicator Lamp': "If this light comes on with the engine running it indicates that an exterior light failure."

- Then the engine died and I had to push the car to the parking lot.

- After spending about 15 minutes eating I proceeded to start the car...and it did start!

- I drove about two minutes and got stuck in a long stop light and then the 'Check Engine' light went on and then everything died so I had to push it into another parking lot where it is now sitting.

- The battery is about 6 months old.

- I just bought the car and the seller said something about how the car was conking out on him - but then he said it didn't seem to do that anymore so I bought it.

- The car ran fine earlier that day with no idiot lights going on while it was still light. Don't know if the headlights were what killed it or not.

- Lastly, the first night I checked out this car (last week), the red battery light was on while the car was idling but it would go out when I accelerated. I described this last point to a mechanic and he said it could be the voltage regulator or the alternator...but this was before all this other stuff happened.

If anyone can tell me what might be going on I would greatly appreciate it. And if you think it is a voltage regulator or an alternator, are both of those easy to replace in that car for someone that is NOT a mechanic but is handy with tools.

Thanks very much.

Steve
Go to Kent Bergsma tutorial and watch him put in a voltage regulator. Thats what it sounds like, 30$ part at Autopartswearhouse, install with 2 screws under car on the outside of the alternator housing. cheap and easy. start with the cheapest part to eliminate that symptom.
 

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Have your batt and alt. tested. Should be free at most places. If things are to spec. Replace the voltage regulator and over voltage protection relay as these are common issues and the newer parts are revised (cheap fix, and considered a tune up if original). Wouldn't be surprised if it solved most your issues?
The test of battery and alternater is not conclusive, that's why the dash lights don't come on in any of these cases I have read about. Voltage regulator will cause all sorts of weird problems, power surges affect so many things in these very touchy systems. That's why most mechanics try to fix the symptoms and never seem to get to the $30.00
15 min fix the voltage regulator. Mechanics wouldn't be able to make much money with that stratagy. This VR problem is so common in these E series it's unbelievable. You can learn a lot just listening to peoples issues and find the commonalities
 

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2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
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Go to Kent Bergsma tutorial and watch him put in a voltage regulator. Thats what it sounds like, 30$ part at Autopartswearhouse, install with 2 screws under car on the outside of the alternator housing. cheap and easy. start with the cheapest part to eliminate that symptom.
Did you join this forum to dig up 2+ year old threads and shout out voltage regulator at every opportunity?

Either way, I'd bet it was the alternator, not the VR.
 

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'95 E300 DIESEL, '91 600SEL, '92 600SEL
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whats the OFFFSET ON THESE 300TE WAGON
Don't hijack threads asking for unrelated info.

Always start your own thread. Your question has been asked & answered ad nauseum, so don't be afraid to use the forum's search features.

Also, filling out and completing your profile will go a LONG way to helping you get the most of this or any other online automotive board.
 
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