Test U: The Fog Lamps Are on Continuously

PINPOINT TEST U: THE FOG LAMPS ARE ON CONTINUOUSLY

U1-U3:

Normal Operation
The fog lamps receive power from the fog lamp relay (when energized) through circuit 478 (TN/OG). When the fog lamp switch (integral to the headlamp switch) is engaged, power is switched to circuit 477 (LB/BK) which flows to the fog lamp relay coil. When the fog lamp relay is energized, the relay allows power from circuit 462 (VT) to flow through to circuit 478 (TN/OG) to the fog lamps.

Possible Causes
- Circuit 477 (LB/BK) short to power
- Circuit 478 (TN/OG) short to power
- Headlamp switch
- Fog lamp relay