On all LD's, the bodies of the front and rear upper clearance / running lights are EXTREMELY well sealed into the coach body. They do not leak when new and probably not leak for many, many years. The front and rear upper clearance light bodies should be removed and replaced onlyt as a last resort. This is because of the difficulty in ensuring the same level of sealing that the factory has provided us in these light installations. Water getting into the coach body in these location can cause lots of damage.
The lower side clearance / running lights are not installed in the coach body but rather in lower side skirting. They are not sealed to the same extent as are the upper lights and replacement is not a big deal for the lower light bodies.
Trouble-shooting inoperative lightsCheck the bulb. If it has burned out, replace it.
If it has burned out, see if it has been partially covered by paint. Apparently, for some LD's, the plastic light lenses were removed before exterior paint was applied (or were not installed until after the exterior paint was applied) and paint got past the masking tape and covered part of the bulb. That caused the bulb to fail prematurely. (Paint causes the bulb to get too hot and the filament goes poof.) So, after few bulb failures, I removed the remaining lenses and cleaned the paint off the upper round light bulbs. No bulb filaments on these lights have failed since then.Check the socket for rust/corrosion
This is not as common a cause for the type of `peanut' bulb used on the LD running/clearance lights as it is for the bayonet base lights as used on the LD license plate lights. It is readily visible when you remove a bulb and the fix is cleaning the socket and bulb contacts and applying a small amount of dielectric grease (think Radio Shack, auto or marine parts store for a source).Check the plastic rivet and metal strips in the socket
On our 2001 LD, there are thin metal strips inside the light body that carry electrical current to and from the bulb socket. These strips are in four sections – two sections, joined to each other running to the bulb socket and two sections joined to each other running from the bulb socket. Problem is, the joining is done with a plastic `rivet' which also serves the function of restraining the strips to the base of the plastic light body. (Bear with me now.) This plastic `rivet' does not always hold the two strips tightly enough together to make a good electrical connection. When that happens, the bulb won't light up. What's the `fix' to a LD light that has this problem? It is to solder the two strips together. (You may find that the strips in your running / clearance lights have been already soldered, as this fix has been applied to some lights used in production.) Later production lights may be made differently. I have not yet soldered the strips on our LD, as I've successfully tried a temporary fix of strip edge crimping to those lights that stopped working. I don't expect this to last and will be trying cold solder first and if that fails, hot soldering. This will be done without removing the light body from the LD.Upgrading the clearance lights
The factory now stocks an LED replacement unit for the red/amber clearance lights for 2006 model years & newer in case you're interested. Call to verify the year, but I think it was 2006. It's an interesting product - Bargman 59 LED for $8 each. The light & lens are one integral piece. There is a pigtail that plugs into the existing bulb socket. You just pop off the old lens cover. Remove the bulb. Insert the fitting on the pig tail into the socket & snap on the lens. With this unit, there is no need to replace the entire fixture and mess with the sealant originally used.Installing new fixtures
The major concern in replacing the factory-installed fixtures is being sure they are VERY well sealed. Under no circumstances should a silicone based sealant be used. The Mother ship recommends not using them except for the overlap joint at the rear ABS end caps.I'd recommend using PR-255, a Polyurethane based sealant manufactured by OSI Sealants, inc. They are based in Mintor, OH, or an equivalent sealant. It is a "window, siding, door & roof sealant", so you should be able to buy it or an equivalent at your local home repair store. It is a sealant the Mother ship has used and I learned of it from them.
Do not just run a bead of sealant around the outside of the running light. The correct way would be to clean off old factory installed sealant to the point where there is a clean surface and space for a layer of new sealant under the new running / clearance light body and put on a coating sufficient that the new sealant will squish out around the edge of the new light when it is screwed into place. Then use craft sticks (tongue depressors) to clean off the excess squished out new sealant, leaving a neat radius on the new sealant around the new light body. Use a damp but not wet cloth scrap to wipe off any new sealant outside and away from the radiused new sealant and let it cure for a day before waxing the paint around the new light body.
Contributors: Don McG, Ron, Larry Wade