E 450 V8-5.4L (2009)
Trailer Lamps: Pinpoint Tests
Pinpoint Test S: The Trailer Lamps Are Inoperative - All
Trailer Lamps
Pinpoint Tests
Pinpoint Test S: The Trailer Lamps Are Inoperative - All
Refer to Wiring Diagram Set 95, Trailer/Camper Adapter for schematic and connector information. See: Diagrams/Electrical Diagrams/Diagrams By
Number
Refer to Wiring Diagram Set 11, Fuse and Relay Information for schematic and connector information. See: Diagrams/Electrical Diagrams/Diagrams By
Number
Normal Operation
The trailer tow connector receives ground through circuit RAT08 (WH). This circuit is the shared ground for all of the trailer lamps.
All the trailer lamp relays share a common ground through circuit GD123 (BK/GY).
This pinpoint test is intended to diagnose the following:
-
Wiring, terminals or connectors
-
Trailer tow connector
-
Trailer
PINPOINT TEST S: THE TRAILER LAMPS ARE INOPERATIVE - ALL
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.
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S1 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, BJB, circuit SBB57 (RD), 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 S2.
No