" I tested the pins on T1 and T2. with fuses to the "top":
T1 left pin 21.8V center pin ~ 0 right pin 23.5V
(should be ~ 12V?)"
I just uploaded to the Files section the data sheet for T1
This voltage regulator is made by many different manufacturers
and in many different voltage configurations, but this
data sheet is typical and is the exact one for the motorloa
chips on my logic board and should be representative for
your KA7812 chips.