Tony Sisson

Car is a 2008 R350 with 140k miles. Car kept dying so I had the battery and alternator tested. Battery came back bad so I replaced it. It was a 5 year old Interstate AGM that made a sloshing sound when moved around. Obviously it was bad to it was replaced with another Interstate AGM. Car was fine for 72 hours. I let it sit for 48 hours and it started just fine. Let it sit for another 12 and it would not start. Went to jump it and the clock kept going round and round and there is a beeping sound that can be heard with the door closed and key out.

This might have to do with it partially but the lock actuator for the trunk went out a few weeks ago. I didn't get a chance to order the new part until today. I did, however, pull the interior light fuse and "ratchet strap" the trunk shut so keep the dash warning trunk open off. New trunk lock actuator will be here tomorrow.

I didn't get a chance to diagnose the issue this morning but I'm just brainstorming ideas for when i get home.

Could the trunk motor or something along those lines still be drawing power and draining the battery?
I've read about the SAM and/or battery module causing problems. The part that sticks out the most is the clock going crazy and the beeping sound when car off and door closed.

efzauner

what alternator tests where done? Did they do a charge current/overvoltage test?
Did they do a power drain test while the battery compartment was open? DId they find anything and isolate the source of any current draw?
This is all documented in the shop manuals...

Tony Sisson

Thanks for the reply. Just the Autozone load test and alternator test via their hand held machine. I am going to do a draw test this evening. I have not gone to a shop as of yet. Just wanted some ideas before I get home and try and draw test. Is it a possibility with the trunk lock actuator removed that the car is thinking the trunk is open and causing a power draw?