Expedition 2WD V8-5.4L (2009)
Trailer Lamps: Pinpoint Tests
Pinpoint Test Y: All The Trailer Lamps Are Inoperative
Trailer Lamps
Pinpoint Tests
Pinpoint Test Y: All The Trailer Lamps Are Inoperative
Refer to Wiring Diagram Set 95, Trailer/Camper Adapter for schematic and connector information. See: Diagrams/Electrical Diagrams/Diagrams By
Number
Normal Operation
The trailer tow connectors receive ground through circuit RAT08 (WH) for all of the trailer lamps.
The trailer tow parking and stop/turn relays share the same ground through circuit GD123 (BK/GY).
This pinpoint test is intended to diagnose the following:
-
Wiring, terminals or connectors
-
Trailer
PINPOINT TEST Y: ALL THE TRAILER LAMPS ARE INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the
connector.
NOTE: Before beginning diagnostics, visually inspect the trailer tow connector for signs of corrosion or damage. Repair or install a new trailer tow
connector as required.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
-------------------------------------------------
Y1 CHECK THE RELAY GROUND CIRCUIT FOR AN OPEN
-
Ignition OFF.
-
Disconnect: Trailer Tow Parking Lamp Relay.
-
Measure the voltage between the trailer tow parking lamp relay pin 3, circuit SBB28 (BU/RD), BJB face side and the trailer tow parking lamp
relay pin 2, circuit GD123 (BK/GY), BJB face side.
-
Is the voltage greater than 10 volts?
Yes
GO to Y2.
No
REPAIR circuit GD123 (BK/GY) for an open. TEST the system for normal operation
-------------------------------------------------
Y2 CHECK THE TRAILER TOW CONNECTOR GROUND CIRCUIT FOR AN OPEN THROUGH THE CONNECTOR
-
Disconnect: Negative Battery Cable.
