Toyota Sienna Service Manual: IG Power Source Circuit
DESCRIPTION
The main power source is supplied to the A/C amplifier when the ignition switch is turned to the ON position.
The power source is used for operating the A/C amplifier and servo motor, etc.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.
1 INSPECT FUSE (HTR)
(a) Remove the HTR fuse from the driver side junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
2 INSPECT A/C AMPLIFIER (IG - GND)
(a) Remove the A/C amplifier with its connectors still connected.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage 
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
3 CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY)
(a) Disconnect the connector from the A/C amplifier.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage
4 CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BODY GROUND)
(a) Measure the resistance according to the value(s) in the table below.
Standard resistance 
REPLACE A/C AMPLIFIER
Rear Blower Motor Circuit
DESCRIPTION
Power to the rear blower motor is supplied from the battery via the RR A/C
relay.
The rear blower motor speed level varies between 0 and 31 based on the voltage
difference measured ...
ACC Power Source Circuit
DESCRIPTION
This circuit supplies power to the A/C amplifier and the illumination for the
clock.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FUSE (ECU ACC)
(a) Remove the ECU ACC fuse fr ...
Other materials:
On-vehicle cleaning
1. INSPECT RADIATOR ASSEMBLY
(a) Check that the radiator and condenser are not
blocked with leaves, dirt, or insects. Clean the hose
connections.
If the fins are blocked, wash them with water or a
steam cleaner.
NOTICE:
If the distance between the steam cleaner and
core is ...
Removal
1. REMOVE REAR DOOR WINDOW FRAME MOULDING
Remove the screw.
Using a heat light, heat the rear door window frame
moulding between 40 to 60 C (104 to 140 F).
NOTICE:
Do not heat the rear door window frame
moulding excessively.
Slide the rear door window frame moulding upward
to r ...
Replacement
1. DISCHARGE REFRIGERANT FROM
REFRIGERATION SYSTEM
SST 07110-58060 (07117-58080, 07117-58090,
07117-78050, 07117-88060, 07117-88070,
07117-88080)
(a) Turn the A/C switch to ON.
(b) Operating the cooler compressor at the engine rpm
of approx. 1,000 for 5 to 6 minutes, circulate the
refriger ...
