Pinpoint Test AE: The Daytime Running Lamps Are On With The Parking Brake Set

WARNING: This page is about a different car, the 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

AE1 CHECK THE DRL PARKING BRAKE RELAY CIRCUIT
- Apply the parking brake.
- Key in ON position.
- Disconnect: DRL Relay 1 C1171.
- Do the DRL continue to illuminate?
Yes : GO to AE4.

No : GO to AE2.
AE2 CHECK CIRCUIT 162 (LG/RD) FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the DRL 1 relay C1171-2, circuit 162 (LG/RD), harness side and ground.
  
  Fig 1: Checking Circuit 162 (LG/RD) For Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to AE3.

No : REPAIR the circuit. TEST the system for normal operation.
AE3 CHECK CIRCUIT 295 (LB/PK) FOR AN OPEN
- Key in ON position.
- Measure the resistance between the DRL 1 relay C1171-1, circuit 295 (LB/PK), harness side and ground.
  
  Fig 2: Checking Circuit 295 (LB/PK) For Open
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes : INSTALL a new DRL 1 relay. TEST the system for normal operation.

No : REPAIR the circuit. TEST the system for normal operation.
AE4 CHECK CIRCUIT 175 (BK/YE) FOR A SHORT TO POWER
- Disconnect: DRL Relay 2 C1172.
- Do the DRL continue to illuminate?
Yes : GO to AE5.

No : REPAIR the circuit. TEST the system for normal operation.
AE5 CHECK CIRCUIT 1032 (WH/BK) FOR A SHORT TO POWER
- Disconnect DRL Relay 3 C1000.
- Carry out the relay component test for the DRL relay 3. Refer to EXTERIOR LIGHTS for component testing.
- Is the DRL relay 3 OK?
Yes : REPAIR the circuit. TEST the system for normal operation.

No : INSTALL a new DRL relay 3. TEST the system for normal operation.