How To Get The Trailer Dome Lights Working On My Enclosed Trailer Connected To A 2010 Ford F150

Question:

I have a 2010 Ford F-150 with the 7 prong connector. I just bought a use enclosed trailer with a 7 prong connector. The trailer has a light switch on the wall says ON/OFF 2 dome lights have light switches on them. When I plug the truck to the trailer all the running lights work. The dome lights do not work. Can you tell me how to go about getting the dome lights working? Thanks,

asked by: Neal P

Expert Reply:

If you are looking at the front of the 7-Way connector the # 4 terminal which is at the 1:00 position will be the 12 volt power connection. If you do not have power run to the # 4 terminal on the 7-Way vehicle connector you will want to run a 10 gauge wire like the #10-1-1, from the positive post on the vehicle battery through a 40 amp circuit breaker like the # PK54540, to the # 4 terminal on the vehicles 7-Way connector. This will give you 12 volt power to the 7-Way.

You will then need to run a 12 gauge wire like the # 12-1-1, from the 12 volt power terminal on the 7-Way trailer connector which should be the #4 terminal at the 11:00 position on the front of your 7-Way to the light switch on the wall of the trailer. This will give you power to the light switch.

You will want to make sure the dome lights are wired to the light switch and that switch is working. Also, that the dome light switches are on and the bulbs working.

I am sending a link to a trailer wiring diagram page that will show the 12 volt power terminals on a 7-Way vehicle and trailer connector.

expert reply by: Jeff D