UV resistant sealant for top of van?

[old-van]

I have done a self build motorhome and did not bother with those gland things to make a water seal where the solar panel wires go in to the roof.

There was good reason for that because the roof is ridged so I figured it would end up much more engineering rather than just run the wires straight through and whacking some sealant on.

I thought in either case I would have to seal and so just chose to seal the wires.

This has worked fine while the sealant works but it degrades after some time, I am guessing due to the uv rays since it is up top.

I don't know what sealant I used at first, probably normal sika or such but I had since been using this stuff which is the same as spray glue but marketed as sealant. As I recall looking at the ingredients and seeing it was just the same single ingredient as the spray glues.

My mum just had a spare can from her motorhome days which she since sold so gave me the can. It has worked well as a quick fix, with quick being the operative term. Quick to fix but also quick to degrade. This has only lasted on average a few weeks before I once again have dripping inside my van where the wires come in and I have used obscene amounts lately yet have still been greeted with a drip which happens to be right above my laptop and now the can is pretty much done.

Any more suitable suggestions which will last a while? Any specifically for vehicles or should I just look for some general UV rated sealant?

[LightweightLouisDanvers]

Why not do it properly now and fit a gland, or is there ceiling material in the way now?

[richhead]

why not just use some window silicone, my windows in my house were fitted 15 years ago and ive never needed to change the sealant.

[x type]

one of these

https://www.amazon.co.uk/Waterproof-Photovoltaic-P...

with this to seal it

https://www.amazon.co.uk/WINDSCREEN-GLASS-SEALANT-...