Section 378 (Heater Control Assembly): Inspection

WARNING: This page is about a different car, the 2004 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.

Inspect Illumination Operation

Fig 1: Inspecting Illumination Operation
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Connect the positive (+) lead from the battery to terminal 8 and negative (-) lead to terminal 10 then check that the illuminations lights up. If operation is not as specified, check the faulty bulb.
Inspect Bulb

Fig 2: Inspecting Bulb
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Using an ohmmeter, apply the tester as shown in the illustration to the test for continuity.

If continuity exists, replace the heater control.

If no continuity exists, replace the bulb.
Inspect A/C Indicator Operation
1. Connect the positive (+) lead from the battery to terminal 1 and the negative (-) lead to terminals 4 and 14.
  
  Fig 3: Inspect A/C Indicator Operation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Push the A/C button in and then check that the indicator lights up.
  If operation is not as specified, replace the switch.
Inspect Dimming Operation
1. Connect the positive (+) lead from the battery to terminal 1 and the negative (-) lead to terminals 4 and 14 while pressing the switch.
  
  Fig 4: Inspecting Dimming Operation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the positive (+) lead from battery to terminal 8 and then check that the indicator dims.
  If operation is not as specified, replace the switch.

Inspect A/C Switch Continuity

Fig 5: Identifying A/C Switch Position & Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TESTER CONNECTION SPECIFIED CONDITION

Switch condition	Tester connection	Specified condition
OFF	-	No continuity
ON	7-4	Continuity

Switch continuity: If continuity is not as specified, replace the switch.

Illumination circuit: If continuity is not as specified, replace the bulb.

Inspect Blower Speed Control Switch Continuity

Fig 6: Identifying Blower Speed Control Switch Position & Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TESTER CONNECTION SPECIFIED CONDITION

Switch condition	Tester connection	Specified condition
OFF	-	No continuity
LO	1 - 8	Continuity
M1	1-6-8	Continuity
M2	1-5-8	Continuity
HI	1-4-8	Continuity

If continuity is not as specified, replace the switch.

Inspect Defroster Mode Switch Continuity

Fig 7: Identifying Defroster Mode Switch & Connector Terminals

TESTER CONNECTION SPECIFIED CONDITION

Switch condition	Tester connection	Specified condition
OFF	-	No continuity
ON	4- 13	Continuity

If no continuity exists, replace the switch.

Inspect Rear Defogger Switch Operation (See INSPECTION ) .
Inspect Security Indicator Light (See SECURITY INDICATOR LIGHT CIRCUIT ) .
Inspect Passenger Airbag Manual On-Off Indicator Operation (See AIR BAG RESTRAINT SYSTEMS ) .