I would disconnect, clean, and re-attach all of your ground points. Don't forget the main ground strap from the body to the motor. If you haven't replaced all of you fuses with copper ones, now would be a good time.

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Could the Over Voltage Protection relay be in play here as well?

 

Could also be the internal regulator in the alternator.....

 

I had checked and prelaced all fuses and checked the contact between body to engine strap all were good...
I shall look into simply this over voltage protection relay thing and also maybe could be as simple as buying a new alternator and see if that is the source of the cars issues...
Thanks guys for your input, these tiny yet annoying issues are tipping me over the edge cos other then that the car is damn near 100% immac in every other way...
I'll see if buying a new alternator or just a second hand one will make any difference....
cheers again.
Jay, is there anywhere with a picture so i know where ALL the ground points are so i can check them?? Where would i find such a diagram?

 

would this alternator be suited for my 1990 300e 24v?
might just jump gun and grab it.
Mercedes 190E 260SE 280SE 300CE 300E 320E 2.6L 2.8L 3.0L 3.2L Bosch Alternator | eBay

 

Up by the right front shock tower you'll see several brown (ground) wire gathered together and bolted down. In the trunk, you'll find the same arrangement. If you haven't replaced the OVP relay, do it. Only spend your money on a OEM Mercedes unit or KAE(ler) unit. All others are junk.

Before jumping for a new or replacement alternator, spent less than $30 from an online source for a new voltage regulator (about $40 @ NAPA ). The VR. Is on the back of the alt, held in place by two phillips screws. A 15 min swap job. Rarely do alternators fail.

Jayare

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Beauituful Jay, thanks for that they are the exact answers i was looking for, other forums weren't as "proactive" in their responses. Thanks again.
I shall order these parts now and hope that it is as simple as that..
With the ground wires in a bunch (shock towers under engine bay etc) are you suggesting to take off and rebunch and bolt down?

 

checked battery when running, 14.90 spike at about 15.5 then back down, so hovered around those.
Does that mean it could be the voltage regulator?
I pulled out the OVP had a look re seated it fuse is ok.

 

That voltage is way too high, a sure sign of a bad voltage regulator, and will destroy the battery and electronics if left unrepaired. I've seen batteries explode due to bad voltage regulator and the repair is ugly and very expensive.

Ideally, at full engine temp and running, you should be seeing around 13.5V when measured at the cigarette lighter, give or take a couple of tenths either way.

Regardless, I would also replace the OVP with a new dealer or KAE(hler) relay.

 

Ssssshhhh*t, ok i'll get on it straight away!
Not easy finding these bits here i have to order from the states, so min. 2 weeks until i can fix it. But good to know...
Its a time bomb now hey... thanks Sbaert!

 

Since you have a little time on your hands while looking for a voltage regulator, you might want to fabricate a cable that lets you monitor voltage while the car is running. I took an old phone charger cord and spliced in a couple of alligator clips so that I can connect my DVM to through the lighter socket and monitor voltage while the car is running. Its a pretty simple little tool and you might be able to improve on the design. It could be useful now or in the future.

 

Also, if your battery is old...the alternator is trying to feed it juice while its not holding it therefore alternator is constantly working and fluctuating in electricity depending upon rpms. I put my money on the v regulator and would replace the battery or have it checked out.

 

The battery was in it when i bought it. owned it for only 6 months.
Looks newish, works fine and the colour indicator bubble thing on it says its good with a green light showing so i'm assuming battery is ok. But i'll def jump on that v reg asap. As for making a tool like that def something to try as you suggest i have time waiting for the part...
Thanks for the input staved me attempting to just throw a new alternator in there and hoping that would solve my issues.

 

See this thread - very interesting

http://www.benzworld.org/forums/w124-e-ce-d-td-class/1668677-electrical-gremlins-fix-oh-boy.html

 

Might I suggest the old 'Model T' trick...

Keep your headlights on while running/driving...

It was sometimes necessary to prevent just such an overvoltage condition on those old jalopies!

 

What is the model T trick?
keeping lights on whilst driving? or something else?
I've ordered the new voltage reg.
Do you think its worth replacing the OVP relay to isolate this window "convenience" issue?

 

Guys here is a picture of the old v reg.
It looks completely hammered. So glad i replaced it when i did.

So after throwing in the new one in, it's holding at 14.15v at the battery no fluctuation what so ever.

i like to thank all of you guys for all of your help. I think this ha solved this headlight and all lights flickering issue.

This leaves me with my final electrical issue, the drivers window going down every time i either lock or unlock the car...

Cheers.