Basic Inspection

RESISTANCE MEASURING CONDITION OF ELECTRONIC PARTS
1. Unless stated, all resistance is measured at an ambient temperature of 20°C (68°F). Resistances measured may be outside the specifications if measured at high temperatures, i.e. immediately after the vehicle has been running. Measurements should be made after the engine has cooled down.
HANDLING CONNECTORS
1. When disconnecting a connector, first squeeze the mating halves tightly together to release the lock, then press the lock claw and separate the connector.
2. When disconnecting a connector, do not pull on the harnesses. Grasp the connector directly and separate it.
3. Before connecting the connector, check that there are no deformed, damaged, loose or missing terminals.
4. When connecting a connector, press firmly until you hear the lock close with a "click" sound.
5. If checking the connector with a TOYOTA electrical tester, check it from the backside (harness side the connector using a mini test lead.
Fig 1: Identifying Proper Method For Disconnecting Connectors
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NOTE:
- As a waterproof connector cannot be checked from the backside, check by connecting a sub-harness.
- Do not damage the terminals by moving the inserted tester needle.
CHECKING CONNECTORS
1. Checking when the connector is connected: Squeeze the connector together to confirm that it is fully inserted and locked.
2. Checking when the connector is disconnected: Check by pulling the wire harness lightly from the backside of the connector. Look for unlatched terminals, missing terminals, loose crimps or broken conductor wires.
  Check visually for corrosion, metallic or foreign objects and water; and bent, rusted, overheated, contaminated, and deformed terminals.
  
  Fig 2: Checking Connectors
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  NOTE: When testing a gold-plated female terminal, always use a gold-plated male terminal.
3. Checking the contact pressure of the terminal: Prepare a spare male terminal. Insert it into a female terminal, and check for good tension when inserting and after full engagement.
  
  Fig 3: Inserting Male Terminal Into Female Terminal
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
REPAIR METHOD OF CONNECTOR TERMINAL
1. If there is any dirt on the terminal, clean the contact point using an air gun or shop rag. Never polish the contact point using sandpaper as the platings may come off.
2. If there is abnormal contact pressure, replace the female terminal. If the male terminal is gold-plated (gold color), use a gold-plated female terminal; if it is silver-plated (silver color), use a silver-plated female terminal.
  
  Fig 4: Identifying Proper Methods For Cleaning Of Connector Terminal
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Damaged, deformed, or corroded terminals should be replaced. If the terminal will not lock into the housing, the housing may have to be replaced.
HANDLING OF WIRE HARNESS
1. If removing a wire harness, check the wiring and clamping before proceeding so that it can be restored in the same way.
2. Never twist, pull or slacken the wire harness more than necessary.
3. Never make the wire harness come into contact with a high temperature part, rotating, moving, vibrating or sharp-edged parts. Avoid panel edges, screw tips and similar sharp items.
  
  Fig 5: Identifying Proper Methods For Handling Wire Harness
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. When installing parts, never pinch the wire harness.
5. Never cut or break the cover of the wire harness. If it is cut or broken, replace it or securely repair it with vinyl tape.