Exterior lights on motorhomes are very susceptible to failure due to corrosion. This often is caused by faulty ground connections.
With an assistant, check the operation of all your lights, including brake and back-up lamps. Note any problems and check for burned-out bulbs. If the bulb(s) are good, run a temporary jumper wire with alligator clips from the ground side of the socket to a clean, metal ground on the chassis to test for a bad connection.
Treating Lighting Sockets
Corroded lighting sockets and various other wiring connectors can be treated with a special electrical terminal grease. P/N F8AZ-19G208-AA is available from Ford dealers.
This grease also can be used on battery terminals, and most 12-volt electrical connector applications (not secondary ignition high-voltage connectors or very low-voltage circuits such as sensors).
If a turn-signal flasher fails on your motorhome or dinghy vehicle, you can temporarily substitute the four-way flasher, until you get to a parts store. Of course, if you need the four-way flashers, you’ll have to move the flasher back to that socket.
Make up a kit containing spare light bulbs to replace any that may burn out inside or outside of your coach. This can be especially helpful when dry camping in remote areas where replacements are not readily available.