ES-350 Completely Dead

[PLP]

Few days ago a new alternator was installed at the local Toyota dealer. Car was driven for couple of short trips afterwards and performed perfectly. Now after being parked for 3 days it is completely dead. No remote, no dash light, no signal of anything. I used mechanical key to open the door and than tried starting up with the key fob. Nothing. Key batter is only few months old. Car battery was in  excellent shape just a few days ago. Where do I start...? New battery..?  Could it be related to the new alternator install, wires, fuses...? Or maybe engine immobilizer system...? Unlikely though since there are zero dashboard indicators on. Car is completely dead.

 

Any advice most appreciated

[dewana421]

First thing you need to check is voltage on battery. I bet you it’s completely dead. I would try jump starting it however if it’s completely dead it may not work. It’s highly possible that the new alternator failed and you were running the car on battery juice which eventually gave up. 
mid you are able to jump it I would connect the battery to another car and leave it alone for 5-10mins to get some charge and then try starting it. Make sure all headlights are turned manually off and not on auto. 
if starts then check the battery voltage while car is running. It should be between 14-15 volts DC. If yes than your alternator is good. If it’s around 12 or lower then alternator isn’t working. 
mid battery isn’t that old you should take it out and get a replacement from where you bought it. It should be a free swap. 

[PLP]

dewana421, many thanks for your advice. You gave me little push in a right direction and I actually followed it and got some answers. Based on readings battery seems to be in a good shape. Was completely depleted on Monday but with little boost car started at first attempt. Alternator readouts are somewhat ambiguous. I was getting around 13.2 V or 14 V which is little confusing. I made an appointment with Toyota to let them take look at it. I forgot to check for parasitic draw but if I can find little spare time I'm going test it today.