R129 SL500 battery flat issue

[Small Car]

My 95 car has been faultless but a funny set of events have happened.

Last Sat going to get a full set of tyres the ASR light came on and the car went in to limp mode - the first time ever. Post new tyres being fitted the problem went away. I parked it up on Sat unlocked (always do in the garage) and on Tues the battery was flat (not drained but not enough to start it). I charged it and started it on Thursday night. At 7am the next morning it had drained again. I am in the process of charging again to get it running. It is an 18 month old battery and I have had no problems with it since being fitted. Could the battery being drained be linked to the ASR issue ? Any thoughts ?

Thanks in advance.

Small Car.

[Small Car]

I have got it running and the ASC is on permanently now so assume the fault is draining the battery ? Any thoughts ?

G

[r129sl]

Were the battery not so new, I would suspect that. Is it a quality brand?

[Small Car]

Yep Bosch £100 jobbie.

[waterden]

I have a 1991 500SL which suffered from this. It turned out to be one of the ECU's shorting. I had this sorted for a couple of hundred pounds and it's fine now. You'll have to get someone who is good on Merc diagnostics because the electrics are complex even on the R129

[Small Car]

Waterden

Thank you and welcome to the fold ! Thank you for your comments. Helpful.

I have some more to add now, but still not sorted some weeks post the first problem. The garage said it was the alternator. Sounded plausible and £222 later it was sorted. Three days later it was flat again and has gone back there. 'Needle in a haystack' and remains there. Think they are scared so it will be going to a Merc specialist. Arghh !