Toyota Tundra Service Manual: Headlight Dimmer Relay

On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. INSPECT HEADLIGHT DIMMER RELAY

(a) Remove the headlight dimmer relay from the engine room relay box.

(b) Check the resistance.

(1) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 - 5	Battery voltage not applied to terminals 1 and 2	10 kΩ or higher
3 - 5	Battery voltage applied to terminals 1 and 2	Below 1 Ω
3 - 4	Battery voltage not applied to terminals 1 and 2	Below 1 Ω
3 - 4	Battery voltage applied to terminals 1 and 2	10 kΩ or higher

If the result is not as specified, replace the headlight dimmer relay.

Toyota Tundra Owners Manual