ABS & ASR lights on and car stalling
 

1992 300 CE 154K miles. All of a sudden after running fine I went to start car the next morning and the ABS & ASR light came on and the car would not idle. If I keep foot on pedal it will run but as soon as I take foot off the car dies. Car has a new battery and just put in a new alternator and is working fine.

Any help is greatly appreciated.

First thing to check would be the OverVoltageProtection Relay, behind the battery I think!

ASR/ABS Lights on Car Stalling
 

How do you check the OVP?

I would not bother checking the OVP relay, I would just replace it with the proper replacement part from either M/B or the aftermarket. Your symptoms are those of a failed OVP relay and even if it is not bad [unlikely] it needs to be replaced due to age. The OVP relay can develope internal, intermittant open circuits as well as having the fuse[s] blow due to jump starting the car or crossing the battery cables during battery replacement. Just replace it with a good quality relay and see what happens.