If a/c on, car stalls at low speed & stops
 

I need help diagnosing the cause of the stalling in my automatic, 1992 300TE 4Matic wagon. It has only recently starting stalling, and seems to only do so when the air conidtioning is on. However, it does not always stall with the a/c on, but it has never stalled when the a/c is off, so it makes me think there is some connection between the two. Also, the car only stalls when it is at idle, or just as gas is applied to leave a stop, and once it stalled when I was slowing down for a stop, (under 5 mph). However, the car will start right back up again and then may not stall again for the rest of the day, or, it may stall several times more. Needless to say, it is very frustrating and annoying!

I have searched the archives for a possible cause, but there are no postings that relate it to the a/c. Most involve the mass air sensor, OVP relay, etc., but the symptoms of other posters don't match mine. So, rather than throwing $$ at it blindly, I thought I'd see if anyone thinks/knows if the a/c could be a cause, by voltage drainage, bad relay, loss of vaccum or what. Thanks in advance for your thoughts.

1962 MB 220SEb "Fintail" Sedan
1992 MB 300TE 4Matic Wagon
1995 Subaru Legacy AWD Wagon

Try loss of rpm. That is what is different with AC.

Based on how that affects you, I would look to posts that discuss the idle stabilization system. Sounds to me that your idle system is dead.

It takes a significant amount of power to run an AC unit, so it can stall the motor if your efi system is unable to compensate like stevebfl suggested. Power steering can stall vehicles as well, turn the wheel all the way to one side and you should see a drop in idle speed as the PS pump draws power trying to turn the wheels.

I wish I could help more, but I am completely ignorant on the details of your particular system. I hope you find an inexpensive cure...