Section 428 (Fog Light System): Inspection

WARNING: This page is about a different car, the 2003 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT FOG LIGHT SWITCH CONTINUITY

TESTER CONNECTION

Switch position	Tester connection	Specified condition
OFF	-	No continuity
ON	10-11	Continuity

If continuity is not as specified, replace the switch.

Fig 1: Identifying Switch

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Connector disconnected: INSPECT FOG LIGHT SWITCH CIRCUIT

Disconnect the connector from the switch and inspect the connector on the wire harness side, as shown.

Fig 2: Inspecting Connector Wire Harness Side

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CONTINUITY

Tester connection	Condition	Specified condition
10-17	Constant	Continuity

If circuit is not as specified, inspect the wire harness.

Connector connected: INSPECT FOG LIGHT SWITCH CIRCUIT

Connect the wire harness side connector to the light control and the dimmer switch, and inspect the connector from the back side, as shown.

Fig 3: Connecting Wire Harness Side Connector

SPECIFICATION CONDITION

Tester connection	Condition	Specified condition
10-Ground	Light control switch HEAD and headlight dimmer switch LO and fog light switch ON	No voltage
10 - Ground	Light control switch HEAD and headlight dimmer switch HI or FLASH and fog light switch ON	Battery positive voltage

If circuit is not as specified, inspect the wire harness.

FOG LIGHT RELAY: INSPECT ENGINE ROOM R/B RELAY CIRCUIT (See INSPECTION )
HINT:

The foglight relay is built in engine room junction block. Also, the relay is constructed with a relay block that is in the junction block as a unit. To disconnect the wire harness connecting with relay block is impossible. If the relay has a malfunction, replace it with junction block assembly wire harness together.

Fig 4: Inspecting Built Relay
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