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Had a rather harrowing experience today stalling at 75 mph in the left lane of 3-lane traffic (yeah I was passing). Somehow made it to the right shoulder, but this just can't happen, especially with my son behind the wheel. Here are the symptoms. Any ideas on a diagnosis would be greatly appreciated.

* Car stalled a couple of times at low-speed (10-15 MPH) 2 months ago.
* *All* the dash lights came on then, and was the same case today.
* Starts right back up (with a little extra cranking than normal) and seems to run completely normally.
* Based on several threads here, I swapped out the OVP with a Mercedes OVP from Pelican Parts. No more stalling until today, and patted myself on the back, thinking the problem was solved. I don't think it's the OVP.

Thanks a lot for any insight.

Dack
 

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What is the voltage at the battery with the car running and electrical consumers like headlights, blower motor running etc..It needs to be 13.4v at a minimum. Have the fuses been replaced with copper ceramic type?

These cars are very sensitive to correct, constant voltage.

Jayare

Sent from my XT1710-02 using Tapatalk
 

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Wow Jayare, thanks for the tip on the fuses. I have read loads of posts on stalling since it first happened and have not seen them as a possible cause. I will start there. Mine are certainly the original aluminum/plastic.
 

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Wow Jayare, thanks for the tip on the fuses. I have read loads of posts on stalling since it first happened and have not seen them as a possible cause. I will start there. Mine are certainly the original aluminum/plastic.
As important or more so is the running voltage. Hopefully you have a multi meter.

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Thanks tuttebenne. I should've noted that the fuel pump relay was replaced as part of a nightmarish running issue that was successfully resolved in 2018.
 

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Ignition control module?

I've had similar issues as you and it certainly is alarming at high speed. Over the years I've resoldered and replaced OVP and fuel pump relays but still had this issue. It was resolved by replacing the ignition control module.
 

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Hey Tuttebenne I removed it this morning and did not see any date code on the part (or at least anything I recognize as a date code). Here is a picture. Any clues?
I see what you mean. I checked a couple of spares that I have and of the black plastic cover type, I have a KAE and an original Mercedes relay. The KAE has a date code painted on it but the one from Mercedes only has a very small stamped code right under the bar code in your picture. Mine says "069C" but I don't know what that means. I see yours has a stamping too but I can't help you figure out what it means. The old metal cover type had a date code printed on them. Sorry I can't be of more help. But what I could offer is the next time it stalls, as you safely coast to a stop, before you restart the car, see if you can hear the fuel pump(s) running. I know that in some situations this might not be possible to hear or you might just want to "get the hell out of there" but its a suggestion nonetheless.
 

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On the back of the alternator you should be able to see a voltage regulator.

If it is the type that has two screws to remove it, it should be easy enough to remove & to check the two brushes, upon removal.

It is also a pretty cheap part to purchase (Bosch is good). Get your part number from the backside and try to find one for sale on E-bay.

When the brushes wear down from 1 inch in length to 1/4", the dash lights flickering will be one indication.

It can leave you stranded and the car won't start.

It is an easy DIY fix, cheap, and can save you a lot of grief & expense.


I don't know if this is the problem, but it is simple enough to check it out.
Your symptoms sound close enough to a faulty voltage regulator- why I mentioned it.
 

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Discussion Starter #12
What is the voltage at the battery with the car running and electrical consumers like headlights, blower motor running etc..It needs to be 13.4v at a minimum. Have the fuses been replaced with copper ceramic type?

These cars are very sensitive to correct, constant voltage.

Jayare
OK please don't judge me but I bought a fuse kit, pliers, and brass brush from Mercedes Source. The fuses look very high quality. The pliers turned out to be useless; on the W124 it's much easier to remove and replace them by hand.

Hopefully this resolves the issue, and if not will continue going down the list posted in the thread.
 

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Hey just wanted to follow up on this thread in case anyone else is having a stall issue at speed with a known good OVP. I replaced the original fuses with the copper/ceramic ones recommended by Jayare and have not had any stalling problems in the 5-6 months since.
 

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Great and thanks for the update. I was gonna suggest checking the CKP out too.

A LOT of people forget that there are two torpedo fuses just inside that screw-down box adjacent to the normal fuse box. Nobody had ever checked/replaced those in my car and they looked like Hulk DNA.

Kevin
 

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OK please don't judge me but I bought a fuse kit, pliers, and brass brush from Mercedes Source. The fuses look very high quality. The pliers turned out to be useless; on the W124 it's much easier to remove and replace them by hand.

Hopefully this resolves the issue, and if not will continue going down the list posted in the thread.
Kent's loving you as his daughters make daily bank deposits from online sales....lol.

Seriously though, most of his in-shop made tools do the task they are meant to do, but they're far from Snap-on. I don't think there are any fakers yet when it comes to ceramic body, copper strip torpedo fuses. You got done what was suggested you do. (y)

Kevin
 
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