Up and down lights, is there a problem??

[mg123]

Hi guys,

I've got quite a few up and down lights outside of my house. 4 on the front of my garage, 1 on PIR and 1 on a switch at the front of my house, and added 6 to the new extension.
Something I've recently noticed with them. the top lights are no longer functioning as they should. They've all become really dim and barely light up. There are several different brands of fixtures, as well as different bulbs. But they all experience this issue.
Do any of you know what causes this, or maybe you've had a similar issue to me? Or perhaps any recommendations to prevent the issue.
I'm really p***ed off with the issue. I guess its something to do with the sun perhaps as it only impacts the top lights.
The bulbs are from reputable source. The garage lights were added early last year. They've not been in use this year as I had a rewire done which meant they're not currently wired in as i'm still doing some work.
The ones at the front of the house were added when the rewire was done by the electrician, and these are the ones I noticed this issue first.
I then tested the ones from the garage and newest ones on the extension. Almost every bulb that's fitted in the up position suffers with this issue.

Any ideas?

 

[Sideways]

Most likely in my view would be a simple case of inadequate design of weather sealing.
Rain will want to run into the upward pointing lights and flow downhill so it will naturally tend to find it's way into the connector with the lamp, into the contacts and even get drawn into the wires between the strands of copper. In all places it will cause corrosion over time and that could cause these problems.
If the bulbs themselves are any good, they will be hermetically sealed. If you were to remove the bulbs and clean them, they should work fine in a good fitting. That would prove the source of your problem.

 

[Sideways]

I don't see any solution to this other than only using good quality light fittings that avoid this problem from the outset.