Replacement of the domed roof lights

I thought I would just post this information as I have seen it posed as a question on a number of occasions, and like me, many wanted to know when someone had actually done it but that was never forthcoming. Well I’ve done it today and thought I would share my experiences with anyone who would like to know. Sorry no photos or video as I now find it all too much of a hassle for me to post them on the new forum due to their size restrictions. Instead I will try to describe my actions well so as not to leave uncertainty or confusion.

My Bessacarr motorhome is just over 4½ years old and was fitted with 3 of those smaller dome topped roof lights. Two had clear Perspex and the bathroom one had opaque heavier Perspex and was more flat than a domed shape on the outside. As you will all know they have permanent ventilation and can be raised on one or both sides by squeezing the handles to release the locking bars and pushed up on their spring fittings. Mine had slotted ventilation spaces that ran parallel to the four edges.

The clear ones seemed to have different Perspex on the inner cover to that on the outside and it had been getting more and more opaque with the passage of time and was cracking with small parts of the edge actually breaking off.  The outer Perspex was not damaged at all and they remained watertight, but I guess one day they would eventually break completely on the inner Perspex so I decided to change them.

Swift said they were made by MPK and mine were 400 size, although I couldn't readily see the MPK logo on the fitted ones until I had removed them. That figure was similar to the opening but it was not 400mm and the extremities were much greater than 400mm so I was a little concerned that the replacement ones were actually the same fittings. Especially when the interior ventilation horizontal slots in the new ones were now two sets of slightly curved ones running front to back only but I had noticed my friends newer caravan had the same shaped vents in his. The inner Perspex also appears to be the same as the outer so perhaps an improvement in materials. I bought them through my dealer from a company called Crusader Products who I think only deal with the trade. They were clearly marked MPK and came with simple fitting instructions but not as detailed as what I am going to describe for you.

To replace them was really easy. All you need is a special style of screw driver; I think it may be called something like a hex fitting and looks like a small starred Allen Key.

I raised the roof lights and then unscrewed the four small screws from the ends of the spring bars holding the dome to the roof opening. Then you have to pull slightly on the ends of those bars to remove them from the housing that is fitted to the roof opening frame. Just lift the domes off from the outside.

Replacement is a simple reversal. I found it easier to fit one end of each side first, getting the end of the spring arm located over the plastic fitting that sticks out from the roof frame. The second on each side can then be located with a bit of tension and fiddling to make sure it actually fits correctly where the cut outs are. You can easily see what I mean when you look at the actual ends of those spring bars. It only goes back one way to be flush so you cannot get it wrong and the tension needed to snap the last ones in place is not a great deal. Tighten the original screws up, but not too tight.

Hey presto, all done and a correct snug fit so my apprehension they may be a little different was not warranted.

Whilst I was doing this, and having found it so easy, I took the opaque bathroom light off and gave it a good clean inside. You cannot take them apart really for fear of not getting them back together so I used a good solution of soapy water and some of those assorted bendable bottle brushes to get in between the domes and then finally a good hose pipe to jet away the debris in between before drying with a hairdryer and replacing as described above.

I hope this helps. Regards, Roy