Toyota Prius 2010 Repair Manual page 202

IG Power Source Circuit
DESCRIPTION
The main power source is supplied to the A/C amplifier when the power switch is on (IG).
The power source is used for operating the A/C amplifier and servo motor, etc.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT:
Turn the power switch on (IG) before inspection. Check the IG1 NO. 1 relay or auxiliary battery if the power
source does not change to on (IG).
PROCEDURE
2010 Toyota Prius Repair Manual