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?

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.

So I finally figure out what the problem is... THE FUEL PUMP RELAY = $156 at the local import repair shop (quite cheap by comparison to what the M-B dealer wanted), AND THE VERY NEXT DAY, the car starts fine in the morning. I go to work and go to start the car on the way home. It starts, runs for about 2-3 seconds and dies! WTF!

I've owned 6 BMWs, all with over 200K on the clock and NOT ONE OF THEM has EVER left me on the side of the road, let alone this kind of Mickey Mouse crap. I've owned two Benzes and I swore I'd never own one again after the first one... fool me twice, shame on me! What a POS! Anybody want to buy an 87 300E cheap?

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....

Three post to make your point , and you are still full of B.S.....

http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1987@@1987&makeid=63@@MERCEDES+BENZ@@X&modelid=6199%3AMBC%7C1507%3AED%7C10000013@@300E&catid=241959@@Body+Electrical&subcatid=241990@@Fuel+Pump+Relay&applicationid=W0133-1610513&mode=PA

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A Dalton

I had a problem that was sort of like this, except it turned out to be a leaky vacuum hose, the one to the cold start injector.....

Anyway, at first until it went totally bad and started stalling ALL the time, it would stall out at stop lights. At first, only when the AC was on due to the extra load it put on the motor.

M103 has 3 hoses that like to leak and kill the motor. They get hard and brittle and crack in places that are hard to see.

Anyway, it's easy enough to check if you don't get results with the other suggestions here. Those hoses will go bad eventually..........

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-tp


1990 300SE "Corinne"- 145k daily driver - street modified differential - PARTING OUT OR SELLING SOON - PORTLAND OR. AREA - PM ME FOR DETAILS
1988 560SEL "Gunther"- 190K passes anything except a gas station
1997 S420 - 265k just bought it with a rebuilt trans. Lovely condition