Toyota RAV4 Service Manual: Blower motor circuit
Description
When the heater control (blower switch) is set to position 1 or higher, the contact of the htr relay is closed, current flows to the blower motor, and the blower motor operates. The blower motor speed can be changed by exchanging the ground and the blower resistor circuit with the heater control (blower switch).
Wiring diagram
Inspection procedure
- Inspect fuse (htr)
- Remove the htr fuse from the engine room no. 2 Relay block.
- Measure the resistance of the fuse.
Standard resistance:
below 1
- Inspect heater relay (marking: htr)
- Remove the heater relay from the instrument panel junction block.
- Measure the resistance of the relay.
Standard resistance 
- Inspect blower motor
- Disconnect the e54 motor connector.
- Connect the positive (+) lead from the battery to terminal 2 and the negative (-) lead to terminal 1, then check that the blower motor operates smoothly.
Ok: the blower motor operates smoothly.
- Measure the current.
Standard current 
- Check wire harness (heater control (blower switch) - battery)
- Disconnect the e24 heater control connector.
- Measure the voltage of the wire harness side connector.
Standard voltage 
- Inspect heater control (blower switch)
- Remove the heater control.
- Measure the resistance of the switch.
Standard resistance 
- Inspect blower resistor
- Remove the blower resistor.
- Measure the resistance of the resistor.
Standard resistance 
- Check wire harness (heater control (blower switch) - blower resistor)
- Disconnect the e24 heater control connector.
- Disconnect the e55 blower resistor connector.
- Measure the resistance of the wire harness side connectors.
Standard resistance 
- Check wire harness (blower resistor - blower motor)
- Disconnect the e55 blower resistor connector.
- Disconnect the e54 motor connector
- Measure the resistance of the wire harness side connectors.
Standard resistance 
- Check wire harness (blower motor - body ground)
- Disconnect the e54 motor connector.
- Measure the resistance of the wire harness side connector.
Standard resistance 
- Measure the voltage of the wire harness side connector.
Standard voltage 
- Check wire harness (air conditioning amplifier - battery)
- Disconnect the e36 amplifier connector.
- Measure the voltage of the wire harness side connector.
Standard voltage 
- Check wire harness (air conditioning amplifier - body ground)
- Disconnect the e36 amplifier connector.
- Measure the resistance of the wire harness side connector.
Standard resistance 
Proceed to next circuit inspection shown in problem symptoms table
Multiplex communication circuit
Description
The air conditioning amplifier communicates data with the ecm and combination
meter through the can
communication system.
Wiring diagram
Inspection procedure
Check dt ...
Compressor circuit
Description
When the a/c switch is turned on, the magnetic clutch on signal is sent from
the air conditioning
amplifier. Then the mg clt relay turns on to operate the magnetic clutch.
Wiring diag ...
Other materials:
Ig power source circuit
Description
This is the main power source supplied to the air conditioning amplifier when
the ignition switch is on
(ig). This power source is used for operating components, such as the air
conditioning amplifier and
servo motors.
Wiring diagram
Inspection procedure
Inspect fuse (ec ...
Throttle actuator control motor current range / performance
Description
The etcs (electronic throttle control system) has a dedicated power supply
circuit. The voltage (+bm)
is monitored and when it is low (less than 4 v), the ecm determines that there
is a malfunction in the
etcs and cuts off the current to the throttle actuator.
When the volt ...
Seat position sensor
Components
On-vehicle inspection
Check seat position sensor (vehicle not
involved in collision)
Perform a diagnostic system check (see page rs-
49).
Check seat position sensor (vehicle
involved in collision)
Perform a diagnostic system check (see page rs-
49).
Ev ...
