POWER TRANSISTOR (For Rear Heater): Inspection

WARNING: This page is about a different car, the 2006 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT POWER TRANSISTOR
1. Connect the positive (+) lead to terminal 1 through a 12 V - 3.4 W test bulb and negative (-) lead to terminal 2.
2. Check the test bulb comes on when another positive (+) lead is connected to terminal 4 through a 12 V - 3.4 W test bulb. If operation is not as specified, replace the power transistor.
  
  Fig 1: Checking Test Bulb
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure resistance between terminal 3 and 4.
  Standard resistance: 2.0 to 2.4 kΩ
  
  If resistance is not as specified, replace the power transistor.
  
  Fig 2: Measuring Resistance Between Terminal 3 & 4
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002