Pinpoint Test A : All The Trailer Lamps Are Inoperative
WARNING: This page is about a different car, the 2019 Ford F-550 Super Duty, 2019 Ford F-450 Super Duty, 2019 Ford F-350 Super Duty, and 2019 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
- A1 CHECK THE TRAILER TOW GROUND CIRCUIT FOR CONTINUITY TO GROUND
- Ignition OFF.
- Disconnect: Trailer.
- Disconnect: Negative Battery Cable.
- For 7-pin 5th wheel connector, measure:
Positive Lead Measurement / Action Negative Lead Pin 2 Ground
- For 4-pin and 7-pin trailer connector, measure:
For 4-Pin Connector
Positive Lead Measurement / Action Negative Lead 4-Pin Connector, Pin 4 Ground For 7-Pin Connector
Positive Lead Measurement / Action Negative Lead 7-Pin Connector, Pin 2 Ground
Is the resistance less than 3 ohms?
Yes The vehicle is operating correctly. SEND the trailer to an authorized camper/trailer repair facility. No GO to A2 - A2 CHECK THE TRAILER TOW GROUND CIRCUIT FOR AN OPEN
- Disconnect: Trailer Tow C4099 (trailer connector).
- Disconnect: Trailer Tow C439 (5th wheel connector).
- For 7-pin 5th wheel connector, measure:
Positive Lead Measurement / Action Negative Lead C439-2 Ground
- For 4-pin and 7-pin trailer connector, measure:
Positive Lead Measurement / Action Negative Lead C4099-2 Ground
Is the resistance less than 3 ohms?
Yes INSTALL a new trailer tow or 5th wheel connector. TEST the system for normal operation. No REPAIR the circuit.