RV electrical Problem.

[Darren Hayes]

Hi everyone, first time using this forum. Looking for some help with an electrical issue on an 81 Trillium travel trailer. None of the break or signal lights are working. Using a four - 7 round adapter. I've confirmed that the vehicle has power and that the wiring harness is also working. The 7 round was a little corroded, so I updated to a new one. I've checked all the wiring connections inside the trailer hatches and they all appear OK, with the exception of the attached photo. There is a lose white wire not connected to anything....can't see where that would go. One taillight cover was full of water. Have cleaned everything and replaced all bulbs. Any suggestions of where the problem may be? Thanks all. Darren




Sent from my iPad using Fiberglass RV

[Raspy]

In your picture there is a fuse holder (black). did you look at that fuse? Also, next to it appears to be a fuse or fuseable link. Did you ohm it? The white wire you mentioned is probably just an extra.

There are two different 7 pin wiring diagrams. Make sure you are using the one you think you are by actually looking for voltage on the correct wires heading to the trailer from the plug. Start at the plug.

Are the bulbs good? Are the socket springs good and pushing the connectors against the bulbs?

[Darren Hayes]

I replaced all of the fuses and the springs are solid. I haven't tried a voltage metre yet. I will pick one up and try to trace the break. The bulbs have all been replaced now and still no lights. I will check the 7 round wiring again to see if it was done correctly. Appreciate the tips.


Sent from my iPad using Fiberglass RV

[Darwin Maring]

White wire is ground. Nothing works without a ground.

[Darwin Maring]

White wire is ground. Nothing works without a ground.

[Gerry Kiernan]

I was also going to suggest that you use a volt/ohm meter and verify that your system is grounded. On most RV's the electrical system is grounded to the steel frame, and the vehicle system is grounded through it's steel frame or chasis. For the lights to work there has to be an electrical ground between the trailer frame and the vehicle chasis. The lack of a proper ground is very often the source of electrical problems in an RV. One wire in the electrical harness connectors will serve as the grounding wire between the two units.
As mentioned above, this is usually the white wire, but not everybody plays by the same rules, so if you can get an electrical circuit drawing for your trailer it will identify the circuits for you, by colour coding.