June 30, 2015

TT #85 Upgrading Rear RV Lights to L.E.D.s

By: Rob Lowe

Featured Picture

OEM Light FixturesOver the last few months, I have consistently noticed that the left rear turn signal on our 2009 RV has been operating intermittently. Each time it was turned on, it might or might not, flash. We could be checking the lights on our towed vehicle and find that they were flashing, yet the RV’s signal was not. Just as one would think the bulb had burned out, it would begin flashing as expected. Occasionally, rapping on the housing with a fist, would bring the light back into operation, sometimes just long enough to leave me thinking it was OK. My first suspicion was that there was corrosion present or at the very least a loose connection since the bulb would light at times.

As you can see in the photo, there are two identical taillight housings on each side of the coach, one mounted vertically in the upright (right side up) position and one mounted vertically but "upside down”. The two backup lights were close to each other. In the lower housing the ‘bright’ light functioned as the ‘Brake Light’ and in the upper assembly the ‘bright’ light is the turn signal. The remaining lights in each bulb assembly were the taillights, while bulbs mounted on the side of the housing were marker lights.


From the time this coach was brand new, we have had problems with water being retained in the upper light assemblies that are mounted ‘right side up’. It would not be unusual for the backup light bulb to be completely submerged in water and occasionally the water would be about one third of the way up the safety reflector in the assembly. In addition, with the lower housings being mounted ‘upside down’ drain holes had to be drilled in what was now the bottom of the assemblies although even with these drain holes, the housings would become waterlogged with algae forming on the inner surface.


I had removed each of the light assemblies just after we took delivery of our coach and vowed I would not do it again, since it was so difficult to access the bulbs. RV taillights are often van or pick up taillights adapted to fit in the rear cap. On our coach, a large metal cover plate on each side needed to be removed to get access to the light housings, then a ‘Z’ shaped metal plate holding the fixtures themselves required some strange contortions to get it loose enough to remove. At this point, you have access to the bulb sockets so that they could be removed and the bulbs and connections inspected. A simple bulb change took well over an hour and required patience to get your hands in just the right position to remove and reinstall the bulb socket.


With the recent light failures occurring so often, I dug into the problem and concluded that the upper signal socket was not properly seated into the housing and was torqued due to its location against the rear cap with insufficient clearance. The twisting was causing an intermittent connection on the signal light as well as water infiltration. I looked at a replacement connector however the ones that fit the housing were similar in size and shape so there was no advantage to be gained by replacing it. The surface of the red lens was also heavily oxidized, notwithstanding frequent wax and polishing efforts, further obscuring the light output.


Even though I do not recommend installing L.E.D. bulbs for RV brake, signal and taillight lighting (for safety reasons), I initially thought I’d simply change to L.E.D. bulbs. That exchange would not properly address the issues since it would leave the socket in place, retain the lens and we would still have algae build up. In addition, if there was any corrosion, experience has shown that these bulbs will not function reliably. This left replacement of the taillight housing as the correct way to deal with the problems. I determined based on the numbers molded on the face of the lens that the lights were left and right taillights for a 1985 to 2005 Chevrolet Astro or GMC Safari vans. (Yes, GM used the same assembly for 20 model years)! I could have replaced the housings with the same or another brand of similar housings however I decided that if I was going to go to all the trouble, the improved performance and updated look warranted going with the L.E.D. version.


Knowing what light fixtures I needed, I did an online search for L.E.D. fixtures and found that Spyder Auto (www.spyderauto.com) sells high quality L.E.D. replacements that I was assured, after contacting their customer service, would drop right into the existing location. They had three versions: Black, Smoke and Red.  The different colors refer to the accent color of the housing with Black being the darkest, Smoke somewhat lighter and Red being "red”. I could have ordered them online, however since I might have to return them if they did not fit given the special configuration of the layout, I thought I would see if I could obtain them locally. A search of auto parts stores in Goshen, IN (where we were located when the issue really became a problem) resulted in none being in stock however two pair of "Black” ones could be ordered to arrive within a week. So we negotiated on pricing and paid just slightly more than I would have paid online plus the additional cost for expedited shipping.  They arrived as promised and I was pleasantly surprised at the quality of the units and the simplicity in making them fit the mounting location.   


They use L.E.D.s for the Marker, Taillight & Brake/Signal functions, and what is nice is that you simply insert a supplied, correctly wired "bulb base” into the RV’s existing brake and signal sockets. The RV’s existing marker light sockets are not used. Each of the RV’s existing Backup light bulbs are inserted into the new housings where a shiny reflector focuses the backup lighting out through clear lenses. I decided to buy four Superbright L.E.D.s (approved for "off-road use” only!) for each of backup light as well. The replacement fixtures themselves are fully DOT approved.

It should be noted that the fixtures on our coach were mounted using specific hardware to contour the double fixtures to the shape of the RV’s rear cap. It is important, if you want the replacements to properly fit, that you replace the hardware, spacers and so on to exactly match what was used to retain the factory original equipment. Each part has a reason for being there and must be replaced/re-used to allow the finished assembly to fit in place as did the original assembly. In the photo above you will notice that the center screws are mounted on some rubber whereas the end one(s) are flush mounted. When the hardware was fully removed I discovered that "well nuts” were used to provide the rubber spacing. The two fixtures are butted tight together however you can see that there is a curve created when the red outer lens is mated to the flat metal mounting ‘Z’ bracket referred to earlier. There was also a rubber seal that is shown at the bottom of the photo of the original assembly below, that if carefully removed, can be used to provide a seal (more visual than physical) between the installed new light assemblies and the rear cap.

After removing the existing ‘Z’ shaped brackets, then the existing fixtures and obtaining new mounting hardware, I then painted the Z brackets to prevent rust. Taking the time to align the two new fixtures into a contiguous unit will reward you with a custom installation that truly looks like the lighting assemblies coming on new coaches. Install the bulb bases provided into the appropriate sockets and seal the sockets by twisting them in place so their grommets form a water tight seal. Since there is no need for large reflectors, the back of the new fixtures have ample room to fit in place and the interference issues with the body rear cap are no longer an issue. I could have completely removed the marker light wiring, however when carrying out the installation for the first time and not knowing if all would perform as expected, I simply taped over the marker light sockets and wrapped then taped their wiring to main harness to keep them from scraping on the metal assemblies.

 LED Lighting Installed

Turning on the lights and inspecting the end result (after re-installing them) was amazing! The improvement in lighting, the modern look and the crisp "On” and "Off” of the signal and brake lights is superb and eye-catching. The Taillight L.E.D.s are simply a dim version of the Brake and Signal lighting. When the brake is applied or a signal light is turned on the taillight increases instantly in brightness, then drops off instantly as the light is powered on and off when either braking or signaling. The side marker lights are dedicated L.E.D. bulbs mounted to provide lighting at 90 degrees to the rear of the coach, all nicely fitted within the existing fixture.(See the little rectangles on the side of the assembly in the photo to the left.)

 If you want to improve the safety and appearance of your RV, replacing the existing rear light assemblies is a great way to go.






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