Replacing lights is quite a simple job; the most difficult part is to ensure that the wiring is correctly refitted so the lights work properly, and that the connections are all sealed properly. As this job was done in conjunction with the rear of the caravan being re-sheeted, the lights had to be measured up to make sure they were fitted straight.
REMOVE THE OLD LIGHTS
The first thing you need to do is to remove the lenses of the old tail lights. In this case, there were three individual lenses attached by four screws each. Once the lenses have been removed, the wires can be cut. The wires are cut instead of removed from the connection point by loosening the securing screw because of the amount of corrosion on the connections.
The idea is to get a sharp knife or side-cutters and snip the wire close to the connection point. This way you can see the colour of the wire connections as a reference point for when the new tail lights are wired up later.
Now that the wires are free, the body of the tail light can be removed from the back of the caravan. You might need to use a plastic scraper to prise the tail light away from the rear sheeting if it was originally sealed with silastic.
With the tail light removed, make sure that the wires protruding from the rear sheeting do not fall back in behind the sheeting – it will be a big job fishing out those wires with a piece of wire or, worst case, removing part of the sheeting to retrieve them.
Clean any evidence of old silastic or dirt from the aluminium sheeting with wax and grease remover and a plastic or Perspex scraper, if necessary. Do not use a metal scraper to remove any remaining silastic as it will quickly damage the paint and the soft aluminium underneath.
PREPARE THE NEW LIGHTS
Now it’s time to prepare the new tail light for fitment. Remove the lenses and be careful to store the screws, as they will not only look better than using old rusty screws if you happen to lose a few of the new ones, but also may have, as in this case, a nylon washer fitted to spread the torque more evenly and/or seal the screw hole from moisture ingress.
If you’re continuing with the original style of tail lights, then all you’ll need to do is to attach them to the same points. If you’re using a different shape of tail lights or you’ve replaced the cladding, you’ll have to measure for the new tail lights so that they are fitted straight.
Get out a steel square and set it up on the side of the van and mark with a pencil or whiteboard marker the horizontal points to guide you in fitting the tail light.
Now the wires can be fed through the back of the tail light body according to the point closest to where they will be connected. Now is the time to check the cut wires on the old tail light as a reference for wiring the new tail light. With the insulation stripped back to expose a clean copper core, screw down the wires to the appropriate poles.
Now you can tuck any excess wire back into the body of the caravan and seal the holes where the wires have come through with silastic. Make sure that the clean-up you did previously includes the periphery of these holes – if there is any old sealer or dirt present the new silastic seal won’t take.
Now the tail light body can be screwed into place with screws. Then the periphery of the tail light body can be sealed with silastic. Wipe away the excess silastic using detergent mixed in water sprayed onto the bead then remove the excess with a cloth.
Now the globes can be installed, making sure you either use gloves to fit them or wipe the glass of the globes with a clean cloth – the oil from your fingers will cause the globes to fail earlier than they otherwise would.
Now the lenses can be attached with the screws and the light checked to see that they all work as they should. Job done!