Lexus Repair: Mechanic cant find electrical pull which kills the battery, time mechanics, old time

Question
My 1996 ES 300 had to be "jump started" last month due to the
antenna motor running and running, the antenna was
disconnected and no problem until yesterday. Drove to the store
tried to start the car..clicking only, had AAA jump start and was
advised to take to mechanic because something was draining/
pulling on the battery and I would have the same problem of it
not starting. I took it in to an "old time" (good mechanics) shop
and they disconnected all fuses and could not find out why
something was draining the battery. They put a new battery in
and it was being drained by I think on the meter it showed
12something.. is that 12 volts or 1200 ? anyway they can't find
out why it did that , I left it overnight and they said today it's not
doing that and they don't know why it did. Any ideas?  Thank
you so much.
Sincerely,
Lin

Answer
Hello, I am not sure you have a problem. The antenna may have been draining the battery before but now it may just be that the battery was bad. The system will always draw 12volts but what needs to be checked is how many amps it is drawing. "Old time" mechanics are good with old time cars but only a factory trained Lexus mechanic is what I suggest. If your battery was anywhere near 2yrs old it was probably just the battery.