Aaaaggghhh!!!

The license fixture looks so innocent, but it was missing a second wire.

It was recently fixed by replacing the original socket with a fixture

that has two wires.

When possible, try to remove old parts before ordering new ones.

This blog post was going to include another video showing how we re-assembled our rear signal lights to make the conversion to LED. However, we had to make some adjustments when putting the lights back in our Airstream. It turned out to be a task that required two sets of hands, meaning it wasn’t possible to videotape the remainder of the process. (Might be looking into a Go-Pro camera.) An explanation of the adjustments will appear in this post shortly.

Since our trailer can’t be in the driveway for very long periods of time, we’ve been changing out all the clearance lights where it’s stored. The signal lights were a lot more involved. The push buttons on the sockets were broken and/or corroded and needed to be replaced. So we removed the cover lenses, rubber seals and the metal cans for each fixture, and brought them back to the house. To remove the cans, you will have to cut the wires that are connected to the light sockets. Make sure you’re cutting close to the cans (the more usable wire left on the trailer, the better), keeping each can’s wire group together, and marking where each wire goes in the series. We used a LED replacement kit. This kit made some of the chore of reinstalling everything much easier. (You will want to cover the openings for the fixtures to keep water out of the trailer, in the event the job won't be completed the same day.)

Why not just use LED replacement bulbs in the existing fixtures? We tried them first. Even though we used LED lights designed for automotive use, they were difficult to see in the Airstream light fixtures. (Old sockets didn’t help.) There are also other considerations when converting to LED lights. If you have an older tow vehicle like we do (1999 Ford Expedition), you may need to add a resistor to one of your 2-pole sockets on each side of the trailer. Otherwise, due to the low power usage of LEDs, your signal lights may not blink. As a side note, we need to make a correction to the previous post. When towing a travel trailer, the only thing pulling power from the trailer’s 12V battery is the breakaway switch. In the event of an emergency where trailer and tow vehicle become separated, it applies the trailer’s brakes. All the light signals get their power from the tow vehicle battery.

This is the signal light kit we used. http://led4rv.com/index.php?main_page=product_info&cPath=15&products_id=292   The owner of this business is very helpful. He not only assisted us with purchase of correct parts and instructions for installing our lights, he even emailed us a diagram explaining how we needed to wire a new 7-way plug on the Airstream hitch cord.

Here are a few other things to keep in mind when changing the signal lights on a travel trailer.

We can’t stress enough to document everything with pictures. Before cutting wires from old fixtures, make note of the wire colors and what is connected where. As we’ve already discovered, some trailer manufactures used their own wire colors for some electrical functions and may not be universal to all. Don’t rely on your memory to make sure you’re connecting everything properly, especially if you need to complete the job at a later date. Many travel trailers, like ours, do not have a lot of air space between the outside shell and interior walls. For the turn signals, we used wire nuts to connect the old wires with the new, just in case we didn’t wire something correctly. Removing wire nuts is a lot easier than cutting and splicing; only to find out you have wired it wrong and need to change the configuration and cut and splice it again. Purchase the smallest wire nuts you can easily work with. If the wire nuts are too big, you might not be able to get a snug, water-tight fit when placing the cans back into their openings. Using enough wire allows the whole configuration to be tucked around the cans.

Two other items should become a permanent part of your traveling toolbox; a tester for your vehicle’s tow package, and another tester designed for your travel trailer. Be prepared to spend a bit of money for a trailer tester, if you want one that can trouble shoot your electrical problems. The correct trailer tester can also serve a dual purpose. It can be used for emergency hazard lighting for the trailer if you must leave it along the side of the road without the tow vehicle. It’s important that this tool has its own source of power for testing your trailer signal lights. (See correction above. The trailer tester we first purchased supposedly worked with the trailer’s 12V battery. Guess what, it didn’t work the clearance/signal lights and has been returned.) Oh, and one more thing. Make sure you keep the owner’s manual for your tow vehicle (or locate one for your vehicle). Sooner or later, something in the tow package will fail, especially when testing new lights on the trailer. Replacing fuses and relays isn’t difficult as long as you know the correct parts and where they go.

Now, back to our tail lights. We put the resistors on the back of the cans initially, and discovered the hard way there isn’t enough room for them between the cans and the interior wall. Next we tried adding the resistors to the side of the can. This too did not allow enough room to fit everything back on the trailer. It turned out they did fit on the inside of the can alongside the socket and still allowed enough room for the LED light fixture. Obviously, it took a bit of trial an error, not to mention time, to make the adjustments.

We spent 4-5 hrs. re-locating the resistors, reconnecting wires and closing everything up. After all that work, we hooked the Airstream to the SUV for a test. (We were still deciding on a trailer tester.) Everything seemed to be working properly until we turned on the vehicle headlights. Then it all went south. We think our culprit might be the new license plate fixture. The trailer originally had two wires, but Karl believes the replacement came with a single wire bulb socket, therefore the circuit isn’t being completed. (Pictures, people, pictures!) When you have incomplete circuits, missing grounds, or shorts your trailer lights will do all kinds of aggravating things. The one thing they won’t do is work properly. Big sigh… That means the license plate fixture will be removed in a few days to correct it. For our next test, we’ll probably be crossing every possible body part to the point of being contortionists, hoping we’re finally ready to move on to the next project. (Replacing holding tanks. Woohoo!!)