By Chris Dougherty
Certified RV technician
These days many new RVs are coming equipped with all LED lighting, which is great. LEDs last a long time and are very energy efficient. The rest of us still have good old-fashioned light bulbs that burn out.
Keeping a selection of light bulbs in your rig’s tool box is a great idea. This way, when you have a burn out, you have a replacement handy. Here again your owner’s manual should tell you what bulbs you need for the various lights in the rig, and I would keep at least two of each. If you don’t have the list, that’s okay — each fixture will say which bulb it needs on the back plate behind the bulb.
Don’t forget appliance bulbs! The bulb sizes will be listed in the appliance manual, or the bulb can be used to match one up, although some of them are specialty bulbs that may only come from an RV appliance service provider or appliance company. Very important, and I can’t emphasize this enough: Do NOT change bulb sizes in these lighting fixtures. Replace them with the exact bulb that was in them!! Here’s why: With interior lights, a larger size bulb is hotter and thus can cause a meltdown of the fixture and a fire. The same goes for exterior lights. Marker, and stop/turn/tail lights must have the same bulb to maintain their FMVSS rating for visibility, and if the wrong bulb is inserted in a tail light, it probably won’t work, or can even blow fuses.
Another problem I have seen is when the wrong style bulb is used in a fixture, like when a stop/tail/turn multi-filament bulb is used in an interior single-filament fixture. This can create a short circuit in the fixture that can cause damage to the fixture or even a fire. Always use the bulb recommended in or on the fixture.