Engine stops running while A/C in AUTO mode (full blast) and radio is ON.
Have no clue what this might be. Can anybody help? PLEASE!

My humble apologies... 87 M-B 300E and I live in Cleveland, Ohio.

Check OVP relay and fuses.

What kind of car is it? Model? Model year??

Where on the planet do you reside? Makes it just a little easier to suggest where parts might be located or experts reside.

__________________
There is a very fine line between "hobby" and "mental illness."
FrankenBenz: '87 560SEC with an '02 cammed LS6 and custom 4L60E.
Bling: '87 560SEC, ported/polished, lowered
Lisa: '87 560SEL, lowered

My humble apologies... 87 M-B 300E and I live in Cleveland, Ohio.

Thanks for the update - it does help!
Could be bad alternator or battery - those are very large electrical loads and could drop the voltage down too low for the system to operate. Should be around 13.8vdc at an idle, around 12.5 with the engine off. Check the voltage with the engine running and no AC, then start turning on things.

Could be a bad ground connection too, but that could be difficult to find.

Autozone or Pep Boys (and others) will check your battery and alternator for free if the voltages are too low.

Any dashboard lights that come on while it's dying?

__________________
There is a very fine line between "hobby" and "mental illness."
FrankenBenz: '87 560SEC with an '02 cammed LS6 and custom 4L60E.
Bling: '87 560SEC, ported/polished, lowered
Lisa: '87 560SEL, lowered

I will check the battery. Today it died again twice with just the A/C on and I can never replicate the problem! The battery is less than 1 year old. The alternator is from auto zone and possibly suspect but the car starts right up after it dies?! And, ALL the lights come on as if I just turned the ignition on.

Update!
My friend from whom I bought the car advises that he had the fuel filter changed and that there is a chance that the tech may have loosened the fuel pump power/ground lead. Does this sound plausible?

Update!
My friend from whom I bought the car advises that he had the fuel filter changed and that there is a chance that the tech may have loosened the fuel pump power/ground lead. Does this sound plausible?

That could be possilbe, but you have to get under there and look. You will have to take the cover off to see, also have you looked at your ovp?

the fuel pump relay 156 dollars? no...totally impossible....absolutely no way the fuel pump relay is more than 40 dollars...who told you this?

you know, you guys seem to get screwed all over the place here, swear to God...

and that's installed out the door...your being a sucker, these are not NASA space shuttles here...they are stupid cars...you are letting preditors take you for a ride....that is your fault, not theirs....

He's right on one thing. The dealership part cost is a LOT higher than the 156.00 listed here in AD's link.

Ask me how I know....

But when you're dead in the water on the side of the road and have read multiple posts on possible causes of engine cut-out followed by immediate restarting, and how many Indies and DIYer's throw money at part after part after part,well, time to call the flatbed and tow to the dealership.

It's all relative.

I believe the post you quoted said there was no way the FPR could cost as much as $156...no more than $40 I believe it said, "unless you are a sucker." Perhaps you meant to quote the OP.

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2012 E350
2006 Callaway SC560

40 dollars huh, what brand are we talking about?

Well, I can't say I had no warning. In fact I was diving home a bit early so that the engine would would have a chance to cool before I pulled the plugs to look at them, and pulled the air cleaner to look at intake manifold fittings [vacuum lines]. If all of them seem good, it's time to crawl under and take a look at the modulator.

What I had observed was for a couple of days, the transmission upshifted much too fast [in top gear before 20 mph] unless I manually downshifted. At highway speeds [over 50] diving felt fairly normal.

About halfway home, the engine just stopped in rush hour traffic. I coasted to a stop on the left median [oops] next to the guard rail. No room to open the hood and tinker. Two hours and sixty dollars later, I was home in my driveway. Hopefully tonight I will finally get some time to tinker with it.