Hello. I have an issue on my w124 1988 300ce. I was at the drive thru last week and I started to get rough idle, ABS light turned on, and my blower motor shut off, when I gave the car throttle, the issue went away, when I stepped on the brake pedal the problem came back. I quickly deduced it was lack of voltage so I turned off the lights and made it home. Tried starting the car right back up again, and no go. Jump started it and checked the voltage at the battery and I had a very slow but steady drop, at 3/4 throttle I'm getting no more than 12.9 Volts peak. Thought it was the alternator, bought a new one, installed it, same issue. Battery is new. What can it be? The infamous OVP?

I've had the rough idle come and go for a bit now, same with the ABS light, car shut off at a light once when I came to a stop. Started right up again. Haven't really had problems with a rough start.

Thanks a lot for the help.