Wiring The 4 to 7-Way Adapter # 30717 to a 1983 Ford Ambulance To Pull a Race Car Trailer

Question:

hello- i have an 83 ford ambulance i use to pull my race trailer. it has seperate amber turn signals, so i bought a convertor to hook up to my 4 blade trailer plug, always worked good. bought new trailer that has 7 blade plug. i also bought an adapter 4 blade to 7 hooked it up and nothing. could the convertor cause this? maybe the blades of the adapter are wired different? ideas? any help would be greatly appreciated. thank you

asked by: Brad

Expert Reply:

If you have the Adapter 4 Pole to 7 Pole, part # 30717, I would recommend using a circuit tester, part # 3808 to test the functions of each pin on the 7-way. I have attached an FAQ Article showing the functions of each pin for the vehicle side 7-Way.

The other thing I would recommend checking is the 7-Way connector on the trailer, to make sure there is not corrosion in the connector. If there is corrosion in the connector, it will need to be replaced.

I would also recommend checking the wiring on the trailer to make sure there are no frayed or cut wires. You will also want to make sure each tail light has a ground connection to a clean metal surface.

To activate the brakes on your trailer, you would need to use Universal Brake Control Wiring Kit, part # 5506, to connect the Black and Blue wires of part # 30717. The Black wire will connect to the Black wire of the duplex cable of part # 5506 and ran to the positive battery terminal via a circuit breaker. The Blue wire will connect to the White wire of the duplex cable and then connect to the Blue wire of the brake controller. You would then need to connect the wires of the brake controller.

I have linked and FAQ on wiring and installing a brake controller from scratch. I have also linked a photo showing the pin functions of the vehicle 7-Way. Also linked is a brake controller installation on a 1979 Ford F-250, that may be of good reference.

expert reply by: Reno H